Image copyright AP Image caption The killings of the four bloggers have caused an outcry in Bangladesh, with protesters taking to the streets throughout the country

Police in Bangladesh have arrested three people, including a UK citizen, over the murders of secularist bloggers Avijit Roy and Ananta Bijoy Das.

Both were hacked to death earlier this year. Police say British-Bangladeshi Touhidur Rahman planned the killings.

Mr Rahman, an IT expert, is said to have links with a banned militant outfit, Ansarullah Bangla Team (ABT).

Police say his arrest will provide evidence about a total of four killings of secular bloggers this year.

The Bangladesh Daily Star reported that Touhidur Rahman was also the alleged financier of ABT.

He and two others were detained last night in the Dhanmondi and Nilkhet areas of Dhaka.

Bangladesh is officially secular but critics say the government has not done enough to stop the attacks.

Media playback is unsupported on your device Media caption Touhidur Rahman, Sadek Ali, Aminul Mollick (front row l-r) were arrested in connection with the murders of secularist bloggers Avijit Roy and Ananta Bijoy Das

Image copyright Getty Images Image caption Niloy Neel was the most recent blogger to die when he was attacked earlier this month in Dhaka

Image copyright Getty Images Image caption All of the bloggers were hacked to death in broad daylight by suspected Islamic hardliners

Last week police arrested two other suspected members of ABT over the killing of atheist blogger Niloy Neel.

Mr Neel was hacked to death by a gang armed with machetes at his home in the capital Dhaka.

In March, another blogger, Washiqur Rahman, was hacked to death in Dhaka.

Image copyright Getty Images Image caption A mourner carries a rose in honour of Avijit Roy

Avijit Roy

Founded Mukto-Mona ("Free Mind") blog site in 2000 to champion secular and humanist writing in Muslim-majority Bangladesh

Bangladeshi-born US citizen on visit to Bangladesh

Engineer by profession

Received death threats from Islamist radicals for his writings, family says

"He was a thinker, he was a man of great knowledge, he was a scientist, he was an engineer" - close friend and Dhaka University professor Anwar Hossain

Image copyright EPA Image caption Ananta Bijoy Das was stabbed to death in the street - in daylight, on his way to work in a bank

Ananta Bijoy Das