Bangladeshi security forces said, on Wednesday, they had arrested three Supreme Court lawyers in connection with funding for an Islamist group to buy weapons.
They had given 10 million taka ($13,000) to the newly formed Shaheed Hamza Brigade, Miftah Uddin Ahmed, head of the Rapid Action Battalion in the Chittagong region told Reuters, adding that they were arrested overnight in the national Capital Dhaka.
It was not immediately clear what led to the arrests.
In April, several brigade members were also arrested in the port city of Chittagong.
Militants have targeted secularist writers in Bangladesh in recent years, while the government has tried to crack down on hardline Islamist groups seeking to make the south Asian nation of 160 million people a sharia-based state.
Three suspected Islamist militants, including a British citizen of Bangladeshi origin, were arrested this week for masterminding the killings of two secular bloggers.
The Shaheed Hamza Brigade was founded by students of a madrassa, or Islamic school, in Chittagong with the aim of armed revolution against the oppression of Muslims around the world, the Rapid Action Battalion said.