The front entrance of the Chinese consulate general in San Francisco was set on fire in an attack on Wednesday night. Chen Gang / China News Service

The FBI and San Francisco police are investigating a fire that was set on Wednesday night to the main entrance of the Chinese Consulate in San Francisco, drawing a strong protest from Chinese officials who condemned the "despicable attack."

The fire happened at 9:25 pm when someone pulled up in a minivan to the consulate, poured gasoline on the front door and ignited a fire, the consulate said in a statement.

Firefighters brought the flames under control minutes later. No injuries were reported.

There were no claims of responsibility for the attack, and police said they had no suspects Thursday morning. Security around the building was increased.

The consulate called the incident "a sabotage of a vile nature" and said China had urged US authorities to launch an immediate investigation.

"The arson attack is a violent crime targeted at the Chinese consular institution in the United States, causing severe damage to the consulate facilities and posing a threat to the safety of the consulate staff and the residents living nearby," said a statement by the consulate. "We urge the US side to take all necessary measures to provide adequate protection for Chinese consular personnel and properties, and bring the culprit(s) to justice as soon as possible."

A spokesperson of the Consulate in San Francisco will brief journalists about the incident at 10:00am local time.