An Islamic militant group said Sunday it has “secured” a U.S. Embassy compound in Libya’s capital city of Tripoli.

American personnel evacuated the area roughly a month ago amid ongoing fighting in the country.

An Associated Press journalist walked through the compound Sunday after the Dawn of Libya, an umbrella group for Islamist militias, invited onlookers inside.

Windows at the compound had been broken, but it appeared most of the equipment there remained untouched.

The breach of a deserted U.S. diplomatic post likely will reinvigorate debate in the U.S. over its role in Libya, more than three years after supporting rebels who toppled dictator Moammar Gadhafi.

A commander for the Dawn of Libya group said his forces had entered and been in control of the compound since last week.

"We've seen the reports and videos and are seeking additional details." a senior State Department official told Fox News late Sunday. "At this point, we believe the Embassy compound itself remains secure but we continue to monitor the situation on the ground, which remains very fluid."

"We continue to work with the Government of Libya and other parties on issues of concern. Our Ambassador and other officials remain engaged both in Washington and from our Embassy in Valetta, Malta, where Embassy staff from Tripoli were recently relocated," the official said.

No U.S. military or assets were guarding the property after the State Department pulled out.

On Sept. 11, 2012, U.S. Ambassador Christopher Stevens, former Navy SEALs Tyrone Woods and Glen Doherty, and State Department information management officer Sean Smith were killed in a terror attack on a U.S. outpost in Benghazi, Libya.

A video posted online showed men playing in a pool at the compound. In a message on Twitter, U.S. Ambassador to Libya Deborah Jones said the video appeared to have been shot in at the embassy's residential annex.

However, two sources with first-hand knowledge of the embassy and other U.S. facilities in Libya say the YouTube video in which the militia members are diving from a roof into pool was taken at the CIA annex in Tripoli that was abandoned when U.S. Embassy personnel and the ambassador pulled out July 26. It is about a mile away from the U.S. Embassy in Libya.

When CIA abandoned the annex in July, it would no longer be considered sovereign US territory.

Jones also said the compound appears to be "safeguarded," not "ransacked."

The fighting prompted diplomats and thousands of Tripoli residents to flee. Dozens were killed in the fighting.

On July 26, U.S. diplomats evacuated to neighboring Tunisia under a U.S. military escort. The State Department said embassy operations would be suspended until the security situation improved.

The Dawn of Libya militia is deployed around the capital and has called on foreign diplomats to return now that the fighting has subsided.

Fox News' Jennifer Griffin and The Associated Press contributed to this report.