A Libyan official said Thursday that the deadly attack on the U.S. Consulate in Benghazi was a planned, two-part operation that included a raid on a supposedly secret safe house -- an account that comports with what a top U.S. lawmaker told Fox News a day earlier.

On Wednesday, House Intelligence Committee Chairman Mike Rogers told Fox News that the strike was a "coordinated, military-style" operation.

Wanis al-Sharef, eastern Libya's deputy interior minister, then said on Thursday the attacks were suspected to have been timed to mark the 9/11 anniversary and that the militants used civilians protesting an anti-Islam film as cover for their action.

The same official also told Reuters that arrests have been made in connection with the investigation. It's unclear whether those arrested are chief suspects. Sharef said four people were in custody and being interrogated "because they are suspected of helping instigate" the attack, but stressed the Libyan government is still "gathering evidence."

Separately, Sharef offered new details about the operation behind the attack Tuesday. He said U.S. Ambassador Christopher Stevens and another official were killed in the consulate, but that the attackers timed a second wave on the safe house just as Libyan and U.S. security forces were arriving to rescue evacuated consulate staff.

He said that second wave killed two more Americans and wounded nearly 30 Libyans and Americans.

The comments continued to contradict initial reports that the attack was a product of angry and violent protests over an anti-Islam film.

Rogers told Fox News he has "no doubt" it was a planned attack and had nothing to do with the film.

"It was a coordinated, military-style, commando-type raid," Rogers said. Based on his own briefings, Rogers said "military movements" were involved.

"This was a well- planned, well-targeted event. No doubt about it," Rogers said. He said the Al Qaeda-linked Imprisoned Omar Abdul Rahman Brigades is one group being looked at by officials.

Senior Obama administrations who discussed the attack late Wednesday could not say whether it was coordinated or spontaneous.

But they, too, described a two-phase assault.

They said the attack started at about 10 p.m. local time on Tuesday, when the main consulate building started taking fire. Shortly before midnight, everybody in that building was evacuated to a nearby annex.

However, at midnight the annex came under fire as well. During the two-hour attack, officials said, two more Americans were killed.

Fox News' Catherine Herridge and The Associated Press contributed to this report.