Authorities are investigating as bias crimes attacks at four locations in New York, including an Islamic centre and a Hindu place of worship, in which molotov cocktails were hurled at the sites damaging property.

The attacks took place in Queens near here last night in which unidentified assailants threw homemade firebombs at a house used for Hindu worship services, Islamic centre Imam Al-Khoei Foundation, a home and a convenience store.

No injuries have been reported so far, police said.

New York Mayor Michael Bloomberg called such attacks unacceptable and said authorities are investigating the incidents.

"No matter what the motivation was of the individual who threw Molotov cocktails in Queens last night, his actions stand in stark contrast to the New York City of today that we?ve built together," he said in a statement.

Governor Andrew Cuomo said such attacks have no place in "our open and inclusive society and we must do all we can to ensure New York remains a safe and tolerant place for all."

Bloomberg said personnel from the New York Police Department?s Hate Crimes Unit and detective squad are "moving at full steam" to investigate and also determine if there are any connections to incidents outside New York City.

A Fire Department official said the attacks damaged property but no one was injured.

Police said in three of the four attacks, Molotov cocktails were made using Starbucks bottles.

The first attack took place last night in a convenience store, also known as a Bodega. Then 10 minutes later, a crude firebomb was thrown at a home, which caught fire, the Islamic centre and the Hindu place of worship.

New York Mayor Michael Bloomberg called the attacks unacceptable and said authorities are investigating the incidents.

"No matter what the motivation was of the individual who threw Molotov cocktails in Queens last night, his actions stand in stark contrast to the New York City of today that we've built together," he said in a statement.

Governor Andrew Cuomo said such attacks have no place in "our open and inclusive society and we must do all we can to ensure New York remains a safe and tolerant place for all."

Bloomberg said personnel from the New York Police Department's Hate Crimes Unit and detective squad are "moving at full steam" to investigate and also determine if there are any connections to incidents outside New York City.

A Fire Department official said the attacks damaged property but no one was injured.

Police said in three of the four attacks, Molotov cocktails were made using Starbucks bottles.

The Imam Al-Khoei Foundation has one of the most prominent Shia mosques in New York.

Police, who are investigating the attacks as hate crime, said callers informed them that they saw the assailants fleeing the scenes after hurling the firebombs.

They were looking at surveillance videos obtained from the bodega and one of the houses that were attacked.

The Islamic centre said on its website that two firebombs were "hurled at the main entrance" but "no major damage, no injury was caused by the blast."

It said the foundation "reiterates its resolve to continue to serve the community and to strive to bring love where there is hatred, light where there is darkness and enlightenment where there is ignorance."

Maharaj was quoted as saying that he rushed from his bed to the lawn after the attack on the temple and found a bottle burning harmlessly. "It smelled like kerosene," he said.

He said he remained alert throughout Monday night, adding that he would continue to conduct his prayer services at his house.

The attacker "should try to find God and be remorseful for what he has done," Maharaj said.

The attack on the temple has been caught on a security camera, and police say the suspect was seen driving a light-colour sedan.

The Queens neighbourhood, where the attacks occurred has several halal shops, Latino restaurants, Hindu temples and storefront Christian churches.

Salem Ahmed, owner of the convenience store that was attacked, said people get along fine in the area and there have not been any problems over the years.

The Yemeni national said a man ran into the store and threw a flaming bottle over the counter.

In the attack on the Al-Khoei Islamic centre, two flaming bottles were thrown at the entrance, causing a small fire. The leaders of the centre are mostly Iraqi immigrants and its members Lebanese.

In another incident, a bottle containing flammable liquid was thrown onto the porch of a house in Elmont.

Residents Bejai Rai and his wife, Hindu immigrants from Guyana, said they heard a loud crash "as if the chandelier had fallen down." Their sons saw a man rushing away into a silver coloured two-door car.

Rai said it appeared that the bottle had bounced off the house and crashed on the concrete walkway. It did not cause any fire.

"We are terribly nervous. If they're going to bomb a house, to burn a house down, they want to kill us. Why would someone want to do that to us," Rai was quoted as saying by the New York Times.