A bomb threat at the Metropolitan Detention Center in Brooklyn forced the evacuation of visiting lawyers on Monday morning, a high-ranking police source said.

The threat was called in around 10:30 a.m. — prompting jail officials to call 911 and authorities to scour the Sunset Park lockup.

Police, however, did not believe the threat was credible, the source said.

The scare comes on the heels of a weekend of protests over the lack of electricity and heat at the federal prison, which houses more than 1,600 inmates who are awaiting trial.

US Department of Justice officials said power and heat were fully restored Sunday at 6:30 p.m.

A few dozen protesters convened outside the jail on Monday, claiming family and legal visitation was still being prohibited. Federal officers armed with long guns stood guard at the entrance. The NYPD was also on scene.

“We asked them if they’re letting any visitors in,” said Molly Pearlman, 25, a CUNY Law student. “All they did was shake their finger no.”

Delores Brown, 50, traveled from The Bronx thinking she’d be able to visit her son.

“They said no visits today until further notice. I’m very disgusted,” she said. “I want to see my son, see how he’s doing. Some of them [inmates] are probably sick from the cold.”

A rep for the MDC didn’t immediately return a message.