WASHINGTON -- The State Department withdrew U.S. security personnel from Libya just weeks before suspected Islamist extremists killed the U.S. ambassador there despite warnings from the U.S. Embassy that the Libyan government couldn’t protect foreign diplomats, according to an email released Tuesday.

The State Department rejected requests to extend the tours of U.S. diplomatic and military security personnel in order to “normalize” embassy operations according to “an artificial timetable,” Eric Nordstrom, the embassy’s former security chief, wrote in an Oct. 1 email.

The claim is certain to fuel a growing election year furor over security at the U.S. consulate in the eastern Libyan city of Benghazi at the time of the Sept. 11 assault that killed Ambassador Christopher Stevens and three other Americans.

Republican presidential candidate Mitt Romney has made the incident a campaign issue, criticizing President Barack Obama over the administration first calling the attack a spontaneous reaction to an anti-Islamic video on the Internet before acknowledging that it was a terrorist operation possibly tied to al Qaida. The White House says that its statements were based on U.S. intelligence assessments at the times they were made.

The email and a list that Nordstrom had compiled while in Libya of 230 security incidents between June 2011 and July 2012 were released by the House Committee on Oversight and Government Reform on the eve of a hearing at which Nordstrom, who is still a State Department security officer, is scheduled to testify.

Lt. Col. Andrew Wood of the Utah National Guard, who commanded a U.S. military security detail at the U.S. embassy in Tripoli, also is to appear. Wood is expected to back Nordstrom’s version of events.

Nordstrom’s list, which he said resulted in a 30 percent increase in pay this summer for embassy staff because of the danger of the assignment, recounted a litany of near-daily bombings, shootings, robberies and other violence. Many involved Islamist extremists and local militias that refused to disband after defeating the forces of the late dictator Moammar Gadhafi in October 2011.

The incidents included a June 6, 2012, improvised explosive device blast that blew a hole in the wall of the U.S. consulate in Benghazi. An Islamist extremist group claimed responsibility.

A July 2012 security assessment included in the list was eerily prescient of what befell Stevens and the three other Americans when some 120 gun- and rocket-propelled-grenade-wielding assailants stormed the consulate in Benghazi just two months later. It warned of a “high” risk that U.S. diplomats, private citizens or business people could be embroiled in an “isolating incident” in which they’d be beyond rescue by Libyan security forces.

“The government of Libya does not yet have the ability to effectively respond to and manage the rising criminal and militia related violence,” it said.

Stevens and Sean Smith, a State Department computer specialist, died from inhaling smoke from fires set by the assailants after apparently becoming trapped inside the main building of the compound. Tyrone Woods and Glen Doherty, both former Navy SEALs serving as security personnel, were killed in a subsequent assault on a CIA safe house.

The name of the person to whom Nordstrom sent the email was blacked out in the version the House committee distributed to reporters.