An underground fire erupted in Astoria on Thursday afternoon, plunging 200 customers into darkness by the evening, authorities said.

The fire broke out at about 2:45 p.m. on 36th Street, between 23rd and 24th avenues. Authorities were trying to determine if it was started by a gas or electrical issue, said Con Ed spokesman Sidney Alvarez.

The blaze reached the street level with flames coming up through the sidewalk, an FDNY spokesman said. The fire was under control about an hour after it started.

By the evening, about 200 customers remained without power, Alvarez said. Another 11 customers, who were closest to the fire, had their gas turned off as a precaution.

Temperatures were expected to drop to the mid 30s on Thursday evening with an 80% chance of precipitation, according to the National Weather Service.

Crews were hoping to restore power sometime in the evening, but it was not immediately clear when that would be.

The blaze appeared to start near a street lamp on the street, with flames coming up a few inches from the ground, witnesses said. A lot of smoke covered the residential block.

John Stavrianos, 23, was with the rest of his family inside their 36th Street home when he noticed the danger.

"I didn't hear anything, but I saw the light flicker and I came outside and saw the fire," he said. It was shooting out of the side of the box at the bottom of the lamp post. Mom was panicking."

Some of the residents who had been evacuated earlier, were allowed back in their homes hours after the flames were brought under control.

The exact cause of the fire was not immediately clear, Alvarez said.