Four people were hurt after a series of explosions rocked the Old World Village complex in Huntington Beach on Saturday evening as the first blast erupted when firefighters at the scene for an electrical fire opened a ground vault, authorities said.

Two firefighters and two patrons had minor injuries from the series of blasts, said Huntington Beach Fire Department Battalion Chief Jeff Lopez.

Hundreds of people attending an Oktoberfest event, with many clad in German garb, stood outside of the village as dozens of police and fire vehicles blocked off Center Avenue and Huntington Beach Lane.

The onlookers watched as paramedics loaded several people on stretchers onto ambulances, which rushed away to a local hospital.

After the blasts, power appeared to be shut off at Old World and a nearby hotel.

“I pray those firefighters are OK,” Dawn Orlow-Townsend, a patron at a nearby restaurant, told KCAL9. “It was crazy, it was so intense. There was a second explosion and then a third. We just started running, we left our cellphones. We were freaking out.”

“It’s the world we live in right now. After the first explosion, you just don’t know what to think. We didn’t know what was going on. The first one, the second one — then there was mass pandemonium. By the third one, we just couldn’t get out of there fast enough, ” Orlow-Townsend said.

Multiple attendees recalled hearing and seeing the explosions take place at about 8:15 p.m. at the shopping and dining complex at 7561 Center Avenue.

One attendee, 26-year-old Megan Houck of Long Beach, said that she saw flames come from the floor near a patio area.

“It was just like one giant fireball that went up,” she said. “And then there was a second explosion maybe 10 or 20 seconds later.”

Houck said that the flames went well above the roof of the village, possibly up to 35 to 40 feet high.

A few minutes before the first explosion, Houck said that the lights had shut off and on. Other witnesses reported apparent electrical problems before the first blast.

In all, Houck said she saw three explosions. Shortly after the third explosion, she evacuated.

Fire officials had originally responded to an electrical fire at the Old World German Restaurant, Lopez said. When fire personnel arrived, the power at the restaurant was on and things seemed operational.

Once they opened up an underground electrical vault to investigate, there was an explosion, Lopez said, injuring two firefighters.

Within several minutes, another explosion occurred.

Fire investigators and utility company officials were investigating the exact cause of the electrical problem and explosions.

City News Service contributed to this article