Updated

Police in Bangladesh on Saturday interviewed former teachers and classmates of a Bangladeshi man charged with trying to blow up the Federal Reserve building in New York, investigating whether he had connections with radical groups at home.

Dhaka Metropolitan Police official Monirul Islam said detectives on Saturday will visit North South University in Dhaka where Quazi Mohammad Rezwanul Ahsan Nafis studied before going to the United States. They were to interview teachers, classmates and school officials.

Bangladeshi detectives have already visited Nafis' village, where they found no evidence of ties with radical groups.

Nafis, 21, was arrested in New York on Wednesday in an FBI sting operation. A criminal complaint says he made several attempts to blow up a fake 1,000-pound car bomb near the Federal Reserve.

Home Minister Mohiuddin Khan Alamgir has pledged that Bangladesh will assist the United States in investigating Nafis.

Nafis' family in the Bangladeshi capital of Dhaka denied he could have been involved in the plot and said he went to America only to study.

U.S. federal investigators, often accused by defense attorneys of entrapping and leading would-be terrorists along, said Nafis made the first move over the summer, reaching out for accomplices and eventually contacting a government informant, who then went to federal authorities.

They said he also selected his target, drove the van loaded with dummy explosives up to the door of the bank, and tried to set off the bomb from a hotel room using a cellphone he thought had been rigged as a detonator.

During the investigation, he and the informant corresponded via Facebook and other social media, talked on the phone and met in hotel rooms, according to a law enforcement official who was not authorized to speak publicly and spoke on condition of anonymity.

Nafis spoke of his admiration for Osama bin Laden, talked of writing an article about his plot for an al-Qaida-affiliated magazine, and said he would be willing to be a martyr but preferred to go home to his family after carrying out the attack, authorities said. And he also talked about wanting to kill President Barack Obama and bomb the New York Stock Exchange, a law enforcement official said.

Investigators said in court papers that he came to the U.S. bent on jihad and worked out the specifics of a plot when he arrived. While Nafis believed he had the blessing of al-Qaida and was acting on behalf of the terrorist group, he has no known ties, according to federal officials.