Police arrived at 4am local time, but most of the women had already heard about the raid and escaped. A number of women were taken on buses to two rehabilitation centres, said Mir Sahabuddin, director of social welfare department.

"The action was taken as a part of the rehabilitation programme," Mr Sahabuddin said.

A spokeswoman for the Tanbazar Movement of Solidarity, a platform of women's organisations, condemned the police action.

"It was totally unnecessary when a process on rehabilitation was going on," she said.

Protests

Lawyer Shirin Huq says a legal challenge wil be mounted to the closure

The brothel in Tanbazar, on the outskirts of Dhaka, was established in 1888. Its official closure two weeks ago came as part of moves to provide alternative housing for the prostitutes working there and to help them find work outside the sex trade.

At least 2,000 sex workers have refused the offer. They fear they will eventually end up in centres intended for beggars. But about 600 others have agreed to move.

On Thursday, the sex workers held a large demonstration against the planned closure. They demanded human rights and women's rights groups be involved in welfare plans for sex workers.

Bangladesh is one of the few Muslim countries where prostitution is legal.

A local journalist said that most of the prostitutes who did not accept the rehabilitation plan were already operating from streets or parks in major cities.