Gilroy city official Dion Bracco said those are preliminary figures following Sunday's shooting.
Witnesses reported confusion and panic as shots rang out at the festival in the city of 50,000 located about 80 miles south-east of San Francisco.
The shooting occurred during the annual garlic festival, a three-day celebration featuring food, cooking competitions and music that attracts more than 100,000 people.
Sunday was the final day of this year's event.
Police have said a suspect has been killed.
Police Chief Scot Smithee said that witnesses reported a second suspect, but it was unclear whether that person opened fire.
Mr Smithee said the suspects had used a tool to cut through a fence to get into the annual garlic festival in Gilroy, California.
He said one of the suspects opened fire and police and officers in the area confronted the suspect in less than a minute.
Mr Smithee said that suspect was shot and killed.
Stanford Medical Centre has two patients being treated from the shooting at the festival, spokeswoman Julie Greicius said.
She had no details on their injuries or conditions.
Santa Clara Valley Medical Centre received five victims, spokeswoman Joy Alexiou said.
She also had no information on their conditions.
Evenny Reyes of Gilroy, 13, told the Mercury News that she spent the day at the festival with her friends and relatives.
"We were just leaving and we saw a guy with a bandana wrapped around his leg because he got shot. And there were people on the ground, crying," she said.
"There was a little kid hurt on the ground. People were throwing tables and cutting fences to get out."
She said that she did not run at first because the gunshots sounded like fireworks.
"It started going for five minutes, maybe three. It was like the movies - everyone was crying, people were screaming."
Todd Jones, a sound engineer, told the newspaper that he was at the front of the festival's Vineyard stage when he heard what sounded like a firework.
"But then it started to increase, more rapidly, which sounded more like gunfire, and at that point people realised what was happening," he said.
Natalie Martinez, a Gilroy resident, told the newspaper that she had gone to get food and separated from her two daughters.
"I ran to find the girls and we basically ran into each other.
"I thought, We're open prey. It was awful."
Video first posted on social media sites about 5.30pm local time showed people running for safety at the festival.
Agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives responded to the scene of the shooting.
Gilroy is a city of roughly 50,000 that is dubbed the "Garlic capital of the world".
The Gilroy Police Department on its Twitter account issued a statement saying: "The hearts of Gilroy PD and entire community go out to the victims of today's shooting at the Garlic Festival."
President Donald Trump tweeted about the shooting, saying: "Law Enforcement is at the scene of shootings in Gilroy, California. Reports are that shooter has not yet been apprehended. Be careful and safe!" he wrote.