A social activist pays his respects to Avijit Roy, slain US blogger of Bangladeshi origin and founder of the Mukto-Mona (Free-mind) blog site, in Dhaka on March 6, 2015
Bangladesh's elite security force Tuesday arrested three suspected Islamist militants, including a British citizen who police said was the "main planner" of the murder of two prominent atheist bloggers.
Rapid Action Battalion spokesmen said they arrested Touhidur Rahman, 58, and two other "active members" of Islamic group Ansarullah Bangla Team (ABT), which was banned in May over a series of killings of bloggers.
"We've arrested them in the capital today. We can confirm that Rahman is a Bangladesh-origin British citizen. He is the main planner of the attacks on Avijit Roy and Ananta Bijoy Das," Major Maksudul Alam of the RAB told AFP.
"He told us that he is a British citizen," said Mufti Mahmood, the head of the RAB's legal and media division.
Four secular bloggers have been hacked to death in Muslim-majority Bangladesh since the start of the year, including Roy and Das, sparking an international outcry and protests mainly by secular activists in the capital.
Roy, a US citizen who was born in Bangladesh, was murdered in February by a gang wielding machetes in Dhaka. Das, 33, was killed in similar fashion as he headed to work at a bank in the northeastern city of Sylhet on May 13.
The government has vowed to hunt down the killers after facing accusations that too little was being done to stop such attacks.
- Rahman 'shadowed bloggers' -
After studying IT, Rahman worked for about 22 years in Britain before moving to Bangladesh where he became a top aide to ABT's firebrand spiritual leader, according to Mahmood.
"He came to Bangladesh in 2012 and did not go back. He told us that in England he lived in East London," Mahmood told AFP.
Police described the unmarried Rahman as the main planner of the attacks as well as the "main financier" of ABT, whose members are mostly students from private universities.
Rahman shadowed Roy and Das in the days before their deaths, after ABT's spiritual leader ordered the group to carry out the killings, according to Mahmood.
"He used to monitor the targets and their movements. He confessed to us that he also helped Ansarullah Bangla Team financially in different ways," he said.
ABT's spiritual leader is currently in jail in connection with the killing of another blogger in 2013.
A British Foreign Office spokesman in London said it was aware of reports of a British citizen's arrest and was seeking more information from Bangladeshi authorities.
The other two suspects arrested are Sadek Ali, 28, who police accuse of taking part in both murders and Aminul Mollick, 35, accused of helping ABT members flee the country by making them fake passports.
Bangladesh police last week also arrested two suspected members of the group for the murder of Niloy Chakrabarti, who became the fourth blogger to be killed when he was hacked to death at his home on August 7.
Chakrabarti, who used the pen-name Niloy Neel, had posted on Facebook months before his death that he had been followed by two men, but police refused to register the complaint and instead told him to leave the country.
The other victim was 27-year-old secular blogger Washiqur Rahman, who was killed in Dhaka four months ago.
Most secular bloggers have gone into hiding, often using pseudonyms in their posts and some have fled abroad.
Police were also investigating claims made by a third party that Al-Qaeda in the Indian Subcontinent was behind the killings. AQIS has already claimed responsibility for Roy's murder.
In a recent petition to Prime Minister Sheikh Hasina, authors including Salman Rushdie and Margaret Atwood called on her government "to do all in their power to ensure that the tragic events... are not repeated".
Bangladesh is an officially secular country, but more than 90 percent of its 160 million people are Muslim.