Four BNP lawmakers including Ashfia Ashrafi Papia and Shammi Akhter were detained from in front of the party’s Nayapaltan central office around 10:30am.
Police picked them up and took them to the office of Detective Branch of police on Minto Road, said Mehedi Hassan, additional deputy commissioner, Motijheel Zone.
Two other lawmakers are Rasheda Begum Hira and Rehana Akhter Ranu.
The ADC said the lawmakers started demonstration sitting on the road around 10:15am after they found the main gate of the party office locked from inside.
Police asked them to free the road as their sit-in was disturbing vehicular movements in the area, he said.
As they continued their demonstration defying police request, the law enforcers picked them up 15 minutes later, he added.
Shammi started brawling with policemen when they were pushed inside the police microbus. She fell off the vehicle along with a lady constable from the running microbus.
Constable Sharifa was sent to Rajarbagh Police Lines Hospital.
Soon after the detention, Opposition Chief Whip Zainul Abdin Farroque talked to media and criticised the police action.
The four were released around 6:15pm, Farroque told The Daily Star in the evening.