New York police are investigating as bias crimes four Molotov cocktail attacks on Sunday night including one against a mosque with 75 people inside and another against a Hindu place of worship.
No injuries were reported.
New York Governor Andrew Cuomo on Monday assigned state law enforcement officials to assist the New York City investigation, saying the attacks "go against everything we stand for as New Yorkers and Americans," and the Council on American-Islamic Relations condemned the attacks.
The arson attacks occurred over two hours on Sunday night in the borough Queens, police said. The first firebomb hit a convenience store, causing damage behind the counter, and the second hit a private house.
Residents of the home escaped without harm but the fire caused extensive damage, police said.
The third targeted the Imam al-Khoei Foundation, a Shiite organization that provides education, funeral services, counseling and helps organize Islamic pilgrimages to Saudi Arabia, according to its website.
The fourth attack hit a private home where Hindu services are held.
About 75 to 80 worshippers were inside the mosque and some of them attempted to put out a small fire at the top of the door until the fire department arrived, imam Maan Alsahlani said.
"We don't know who did this and we cannot accuse anyone. We will let the police department deal with this," Alsahlani said.
This was the first attack against the mosque, he said.
"Even after Sept. 11, nobody did anything to the center or attacked the center," Alsahlani said, referring to the time of high tension following the 2001 attacks.
CAIR, an Islamic civil rights group, called on police to increase patrols protecting mosques.
"Attacks on our nation's houses of worship must be condemned by all Americans and should be investigated and prosecuted using all available law enforcement resources," CAIR spokesman Ibrahim Hooper said in a statement.
Police said the suspect was a man driving a silver sport utility vehicle. At three of the sites the same type of glass container was used, a Starbucks Frappuccino bottle.
"Attacks such as this 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," Cuomo said in a statement, asking his state police chief and deputy secretary for public safety to aid the city police investigation.