DHAKA (REUTERS, AFP) - Bangladesh has not found any evidence linking a Bangladeshi man charged with an attempted suicide bombing in New York with militants in Bangladesh, police said on Wednesday (Dec 13), but the man had read books by an Islamist cleric convicted for inciting the murder of an atheist blogger.

"We have collected evidence and information from his family members - his wife, father-in-law and mother-in-law," Monirul Islam, head of Bangladesh Police's counter-terrorism unit, told Reuters in an interview on Wednesday (Dec 13).

"In Bangladesh, we have not found any connection or have not been able to identify any of his associates who were or are involved with any terrorist groups."

Akayed Ullah, 27, emigrated to the United States seven years ago but regularly visited Bangladesh, where his wife and child live.

He detonated a home-made pipe bomb on Monday at a subway near Times Square in New York, injuring himself and three passers-by.

Islam told reporters on Wednesday Ullah's wife had told them he used to urge her to read the books of Jashim Uddin Rahmani, a firebrand cleric with links to Islamist extremist groups.

But he said Ullah had no ties with militant outfits in Bangladesh and had likely become radicalised over the Internet after moving to the US.

"His wife said he used to tell her to read the books of Jashim Uddin Rahmani. (He told her) she would know about religion or Islam by reading his books," Monirul Islam told reporters in Dhaka.

Counter-terrorism officers in Bangladesh have been questioning Ullah's wife and her family in Dhaka. Rahmani was jailed for five years in late 2015 for inciting the murder of an atheist blogger.

Islam said his books were easily available online and were widely read by Islamists in Bangladesh.

Police have said Rahmani is the spiritual head of the Ansarullah Bangla Team (ABT), a homegrown extremist group accused of being behind the killings of atheist bloggers, writers and gay rights activists in Bangladesh.

The group has links with Al-Qaeda in the Indian Subcontinent (AQIS).

US media say Ullah, who was the only person to be seriously hurt in Monday's attack, told police investigators he wanted to avenge US airstrikes on the Islamic State in Iraq and Syria group.

His US-based family issued a statement saying they were "heartbroken" by the attack and by the allegations against him.

Bangladesh has been waging a war against homegrown extremism in the wake of numerous attacks by radical groups in recent years. In July last year militants stormed a Dhaka cafe and massacred 22 hostages, including 18 foreigners, in an assault claimed by the ISIS.

Security forces have shot dead more than 70 alleged militants in a fierce crackdown since the cafe carnage.

Last month police arrested an alleged militant from ABT over the 2015 murder of a prominent Bangladesh-origin American blogger in Dhaka.