An official with the Lebanese Red Cross said at least 100 people were killed and more than 4,000 were wounded.

The official, George Kettaneh, said the toll could rise further, reports AP.

Residents of Beirut awoke to a scene of utter devastation on Wednesday. Smoke was still rising from the port, where a towering grain silos had been shattered.

Major downtown streets were littered with debris and damaged vehicles, and building facades were blown out.

At hospitals across the city, people had been waiting all night for news of loved ones who had gone missing or were wounded. Others posted requests for help online.

It was unclear what caused the blast, which appeared to have been triggered by a fire and struck with the force of an earthquake.

It was the most powerful explosion ever seen in the city, which was on the front lines of the 1975-1990 civil war and has endured conflicts with neighboring Israel and periodic bombings and terror attacks.

Civilians carry a person at the explosion scene that hit the seaport, in Beirut Lebanon

According to Germany’s geosciences center GFZ, the blast struck with the force of a 3.5 magnitude earthquake.

It was heard and felt as far away as Cyprus more than 200 kilometers (180 miles) across the Mediterranean.

Lebanon's interior minister said it appeared that a large cache of ammonium nitrate in the port had detonated.

Interior Minister Mohammed Fahmi told a local TV station that it appeared the blast was caused by the detonation of more than 2,700 tons of ammonium nitrate that had been stored in a warehouse at the dock ever since it was confiscated from a cargo ship in 2014.

Lebanon was already on the brink of collapse amid a severe economic crisis that has ignited mass protests in recent months. Its hospitals are confronting a surge in coronavirus cases, and there were concerns the virus could spread further as people flooded into hospitals.

The blast destroyed numerous apartment buildings, potentially leaving large numbers of people homeless at a time when many Lebanese have lost their jobs and seen their savings evaporate because of a currency crisis.

The explosion also raises concerns about how Lebanon will continue to import nearly all of its vital goods with its main port devastated.

There is also the issue of food security in Lebanon, a tiny country already hosting over 1 million Syrians amid that country’s yearslong war.

The port's major grain silo is run by the Lebanese Ministry of Economy and Trade.

Drone footage shot Wednesday by The Associated Press showed that the blast tore open those grain silos, dumping their contents into the debris and earth thrown up by the blast.

Some 80 percent of Lebanon’s wheat supply is imported, according to the US Agriculture Department.

Lebanese man helps an injured man who was wounded by an explosion that hit the seaport, in Beirut Lebanon

The tiny Mediterranean nation's economic crisis is rooted in decades of systemic corruption and poor governance by the political class that has been in power since the end of the civil war. Lebanese have held mass protests calling for sweeping political change since last autumn but few of their demands have been met as the economic situation has steadily worsened.

The size and scale of the Beirut explosion mirrored that of another major disaster involving ammonium nitrate.

In 1947, a ship carrying some 2,200 tons of the chemical compound caught fire in Texas City, Texas, and exploded, causing a series of subsequent blasts at nearby oil facilities and a chemical plant. That disaster killed over 575 people and wounded another 4,000.

Witnesses reported seeing an orange cloud like that which appears when toxic nitrogen dioxide gas is released after an explosion involving nitrates.

For hours after the explosion, the most destructive in all of Lebanon’s troubled history, ambulances rushed in from around the country to carry away the wounded.

Hospitals quickly filled beyond capacity, pleading for blood supplies, and generators to keep their lights on.

For blocks around the port, bloodied residents staggered through streets lined with overturned cars and littered with rubble from shattered buildings. Windows and doors were blown out kilometers (miles) away, including at the city's only international airport.

Army helicopters helped battle fires raging at the port.

The explosion came amid ongoing tensions between Israel and the Hezbollah military group on Lebanon's southern border. Many residents reported hearing planes overhead just before the blast, fueling rumors of an attack, though Israeli military overflights are common.

An Israeli government official said Israel “had nothing to do” with the blast. He spoke on condition of anonymity because he was not authorized to discuss the matter with the news media. Israeli officials usually do not comment on “foreign reports.” The Israeli government offered emergency assistance through international intermediaries.

The blast was stunning even for a city that has seen a 15-year civil war, suicide bombings, bombardment by Israel and political assassinations.

“It was a real horror show. I haven’t seen anything like that since the days of the (civil) war,” said Marwan Ramadan, who was about 500 meters (yards) from the port and was knocked off his feet by the force of the explosion.

Lebanese man helps an injured man who was wounded by an explosion that hit the seaport, in Beirut Lebanon

Beirut’s governor, Marwan Abboud, broke into tears as he toured the site, exclaiming, “Beirut is a devastated city.” Prime Minister Hassan Diab vowed that “those responsible will pay.”

But one of Israel’s top bomb experts, Boaz Hayoun, said fireworks could have been a factor setting off the bigger blast. “Before the big explosion ... in the center of the fire, you can see sparks, you can hear sounds like popcorn and you can hear whistles,” said Hayoun, owner of the Tamar Group, which works closely with the Israeli government on safety and certification issues involving explosives. “This is very specific behavior of fireworks.”

Some of those injured lay on the ground at the port, Associated Press staff at the scene said. A civil defense official said there were still bodies inside the port, many under debris.

Several of Beirut’s hospitals were damaged in the blast. Outside the St. George University Hospital in Beirut’s Achrafieh neighborhood, people with various injuries arrived in ambulances, in cars and on foot. The explosion had caused major damage inside the building and knocked out the electricity.

Dozens of injured were being treated on the spot on the street outside, on stretchers and wheelchairs.

People evacuate wounded after of a massive explosion in Beirut, Lebanon
 

People evacuate wounded after of a massive explosion in Beirut, Lebanon

Outside one hospital, Omar Kinno sat on the pavement, holding back tears. Kinno, a Syrian, said one of his sisters was killed when the blast rocked their apartment near the port, and another sister’s neck was broken. His injured mother and father were taken to a hospital but he didn’t know which, and he was making calls trying to track them down.

“I have no idea what happened to my parents. I am totally lost,” he said.

The UN peacekeeping mission in Lebanon, UNIFIL, said one of its ships in the port was damaged and a number of its peacekeepers were injured, some seriously.

Confusion reigned across the city, as people cleared out of damaged homes or tried to locate family. Motorcyclists picked their way through traffic, carrying the injured.

Reaction of US president, French President

President Donald Trump said the US “stands ready to assist Lebanon," and Secretary of State Mike Pompeo extended his “deepest condolences.”

“Our team in Beirut has reported to me the extensive damage to a city and a people that I hold dear, an additional challenge in a time of already deep crisis,” Pompeo said in a written statement.

At the start of a White House news conference on the coronavirus, Trump said the explosion “looks like a terrible attack.” When asked by a reporter if he was confident that it was an attack, Trump said: “I met with some of our great generals and they just seem to feel that it was.”

French President Emmanuel Macron said in a tweet that his country was sending aid. Iran, Hezbollah’s patron, also said it was ready to help. “Stay strong, Lebanon,” its foreign minister, Javad Zarif, said in a tweet.