In videos posted on the social media, terrfied people could be seen running for their lives.

Witnesses reported hearing multiple rounds fired and that some people were down on the ground. Others said the gunman was armed with a rifle and was dressed in some kind of vest and camouflage fatigues, Los Angeles Times reported.

A medical center in San Jose said it was receiving at least five patients, reported the news paper.

Gilroy Police tweeted: "The hearts of Gilroy PD and entire community go out to the victims of today's shooting at the Garlic Festival. The scene is still active. If you are looking for a loved one, please go to the reunification center at Gavilan College at parking lot B. #GilroyActiveshooter."

The police said: "Witness line and family reunification line: 408-846-0583.
If you saw something today please call that number immediately. Please keep the main GPD line for emergencies only. Media please do not call that line. A media line will be posted soon."

San Francisco's Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) said it is responding to the situation.

"BREAKING: ATF's San Francisco Field Division is responding to the scene of a reported shooting at the Gilroy Garlic Festival in Gilroy, California," read the tweet.

US President Donald Trump reacted to the development and asked people to remain safe.

"Law Enforcement is at the scene of shootings in Gilroy, California. Reports are that shooter has not yet been apprehended. Be careful and safe," Trump tweeted.

California Sen. Kamala Harris  described the situation as 'horrific'.

"Simply horrific. I'm grateful to the first responders who are on the scene in Gilroy, and my thoughts are with that community tonight. Our country has a gun violence epidemic that we cannot tolerate," she said.