Witnesses said AL central leaders, including Prof Abdullah Abu Sayeed, were receiving garlands at the council of the sadar upazila AL at a local community centre when a group was trying to enter the venue. The other faction resisted their entrance, which led to the clash.

Both the factions blasted explosives and vandalised furniture. Police rushed to the spot and brought the situation under control.

Of the injured, municipality unit Chhatra League Convenor Zahidul Islam Raju, Sumon, Razzak, Tarun, Manik and Ripon were admitted to Pabna General Hospital, while others received first aid.

Party sources said the conflict erupted due to the election to the post of the general secretary of the district AL. The supporters of the candidates for the post Ahad Babu and Sohel Hasan Shahin locked into the clash to evict their opponents from the spot, they added.