At least 20 people were injured as police charged truncheon on a BNP procession with black flags in Naogaon district town, marking what it says the ‘democracy killing day’.
Witnesses said leaders and activists of the district BNP and its associate bodies brought out the rally from the party office around 12pm.
When the procession reached Muktir Mor, police intercepted the demonstrators, triggering a clash.
At one stage, police started to charge baton on the BNP leaders and activists, leaving at least 20 people, including four policemen, injured.
The injured police personnel are Inspector Samsul Alam, sub-inspector Shahidul Islam, assistant sub-inspector Humayan Kabir and Nayek Al-Amin.
Police also arrested 11 BNP leaders and activists from the spot, said officer-in-charge of Naogaon Sadar Model Police Station M Tariqul Islam.
A case was filed against the arrestees for carrying out attack on the policemen and obstructing the law enforcers from discharging their duties.