A New York man arrested for attacking an Islamic centre and a Hindu place of worship with firebombs has confessed to his role in the incidents that caused outrage over the weekend, citing personal grudges with people at the targeted locations.

The 40-year old, whose identity has not been released yet, was arrested on Tuesday after the police tracked down his car that was seen at the site of the attacks through surveillance cameras as well identified by few witnesses, police commissioner Raymond Kelly said.

Charges are pending against the man who confessed during questioning that he hurled molotov cocktails using Starbucks bottles at the five locations in Queens, including a convenience store and two other residences on New Year's day.

"The individual is implicating himself in each of the five firebombing cases, citing personal grievances with each location," police spokesman Paul Browne said.

Kelly said the man in custody had been kicked out of the convenience store on December 22 for trying to steal a glass Starbucks bottle and milk and had made threats as he was escorted out of the store.

"When they were pushing him out of the store, he said words to the effect that 'We're going to get even. We're going to get back at you,'" Kelly said, adding the man was motivated by personal grievances with people at each of the locations.

The attacks, being investigated as possible hate crimes, caused outrage among city officials and inter-faith leaders who said such incidents should not be tolerated and the guilty be brought to justice.

Kelly had termed the attacks "a heinous type of crime, particularly when people are sleeping in their homes".

In a statement distributed at the meeting between Bloomberg and religious leaders, the Muslim Peace Coalition-USA said an anti-Islam and anti-Muslim campaign had "made Islamophobia politically acceptable in America" adding that the police was keeping the entire Muslim community under "warrantless surveillance".

Last month a group of Muslim leaders had boycotted a meeting with Bloomberg, citing anger over New York police and federal agents spying on mosques and infiltrating Muslim community centres to garner information on the community.

In a show of support, city Mayor Michael Bloomberg and Kelly joined several Muslim, Jewish and Christian representatives at the Imam Al-Khoei Foundation centre, which was one of the targets, for a news briefing on Tuesday.

"As I said before, we don't know what the motive was," Bloomberg told reporters.

"But in New York City, as you know, we have no tolerance for violence, and certainly no tolerance for discrimination".

Bloomberg said whether it was a "senseless violence or a hate crime... in either case, we're just not going to tolerate it in this city".

Queens Borough president Helen Marshall said the person responsible for the attacks "must be punished to fullest extent of the law. This is terrible. And to just throw bombs when you don't even know who's inside, that's wrong. That's wrong and it's not right for Queens".

While no one was injured in any of the attacks, property was damaged. About 80 people were inside the Islamic centre at the time of the attack.

"We were a little bit anxious and a bit nervous in the beginning because we weren't sure. But now after having seen all the support that we have been receiving it is very reassuring," said Al-Khoei Foundation representative Meesam Razvi.

The Imam at the Al-Khoei centre Maan Al-Sahlani said, "We are one family. If one gets hurt, all the family gets hurt. So, we have to be shoulder to shoulder".

The police had earlier released a sketch of the suspect and surveillance video that showed a man hurling the cocktail at a house that was used for Hindu worship services.

The suspect had been described as a black man, 25-30 years old, 5'8" who drove away in a light coloured sedan.

A USD 12000 reward was also offered for information on the man.