The youth is Morad Molla alias Kalachan, 36, son of Sattar Molla of Dakkhinpara Khalchar village of the upazila.
Local sources said a number of 10 to 12 miscreants had taken position at Lutia Bazar with sharp weapons around 4:30pm and attacked Morad as soon as he reached there.
Severely injured Morad was first taken to Lohagara Upazila Health Complex and then shifted to Narail Sadar Hospital. As his condition deteriorated he was moved to Khulna Medical College Hospital.
Dr Ripon Kumar Ghosh of Lohagara Sadar Hospital, said all of the bones of Morad’s left wrist were cut off and he had several wounds on his body.
Md Mokarram Hossain, officer-in-charge of Loahagara Police Station, said police arrested Iza Kota, son of Bala Kata of Kumri village over the incident.
Previous enmity might be the reason behind the attack, he added.