KABUL, Afghanistan (AP) – A massive explosion believed to have been caused by a rocket shook the Afghan capital late Wednesday near the U.S. Embassy compound, wounding an Afghan security contractor, officials said.

U.S. Embassy spokesman Lou Fintor said the blast did not occur on embassy property, and no Americans were injured. Staff members rushed to a bunker in the compound after the 11 p.m. blast.

“All embassy personnel are safe and accounted for,” Fintor told The Associated Press in a telephone interview.

A U.S. counterterrorism official, who spoke on condition of anonymity because it is still early in the investigation, said the southwest side of the U.S. Embassy’s compound was among the buildings struck in the rocket attack.

The official was not immediately aware of casualties or the magnitude of the attack. It also was too early to say who was responsible.

Lt. Col. Todd Vician, a Pentagon spokesman, said one rocket struck near, but not inside, the U.S. Embassy compound.

The blast occurred inside the grounds housing the state-run television offices, a police official at the scene said. The building is next to the heavily fortified embassy and the base for NATO-led forces in the capital.

The official, who spoke on condition of anonymity because he was not authorized to speak to the media, said the explosion apparently was caused by a rocket fired from southeast Kabul targeting the U.S. Embassy.

U.S. military spokesman Lt. Mike Cody said one Afghan security contractor was wounded.

NATO-led troops in armored vehicles patrolled the area after the explosion.

“It was a very strong explosion near the ISAF (NATO’s International Security Assistance Force) compound and we are trying to confirm its cause,” spokesman Lt. Col. Riccardo Cristoni said.

The NATO force controls security in Kabul.

The explosion comes amid increasingly brazen attacks targeting U.S.-led coalition military forces in Afghanistan, particularly across the country’s south, where remnants of the toppled Taliban government have carried out increasing numbers of bombings and attacks.

Militants occasionally fire rockets into downtown areas, and the threat of being kidnapped forces many foreigners to live in tightly guarded compounds surrounded by concrete bomb barriers and to travel in armored convoys.

But Wednesday’s rocket strike was believed to be the closest to the U.S. Embassy in Kabul since an American-led coalition toppled the hard-line Taliban government following the Sept. 11, 2001, attacks.

In July 2005, a rocket slammed into the center of Kabul, exploding on a roadside near the U.S. Embassy and other diplomatic missions, but there were no casualties and little damage to nearby buildings.

The blast came hours after a vehicle exploded near a U.S. convoy in eastern Afghanistan’s Nangarhar province, killing its driver, U.S. military spokeswoman Lt. Tamara Lawrence said. No U.S. soldiers were wounded.

Another militant blew himself up while making a bomb in his home in Baghlan province, about 95 miles north of Kabul, said provincial Gov. Mohammed Halim Raskh.

The militants’ affiliations were unclear, but remnants of this country’s toppled hard-line Taliban regime have claimed responsibility for violence in recent months targeting coalition and Afghan forces.