Attacks were reported on three U.S. bases in Afghanistan on Wednesday, just hours before ceremonies to commemorate the attacks on the United States last September 11. The U.S. military said a gunman fired on Bagram Air Base, the U.S. military headquarters in Afghanistan, while the Afghan Islamic Press (AIP) news agency said rockets were fired at special forces bases near the eastern towns of Khost and Gardez.

No casualties were reported, but the attacks highlighted the continuing instability in Afghanistan and threat to U.S. interests 11 months after American forces attacked the country to pursue the al Qaeda network blamed for the September 11 attacks.

Lieutenant Tina Kroske, a spokeswoman at Bagram, which is just north of Kabul, said an Afghan national directed "small arms fire" at the base at about 6.30 a.m. (10 p.m. EDT Tuesday) and was taken into custody.

The main road going through the base was shut temporarily as U.S. troops secured the perimeter.

The incident came hours before ceremonies at the base to commemorate September 11, 2001. Officials at the base said a "retreat of flag ceremony" scheduled for the afternoon would go ahead despite the gunfire.

Bagram is the main base for 8,000 U.S. soldiers who are in Afghanistan hunting members of Osama bin Laden's al Qaeda network and remnants of the Taliban regime overthrown last year.

Shortly after the report from Bagram, AIP quoted witnesses as saying that at least four rockets had been fired early in the morning at an airfield in Khost used by U.S. special forces.

The Pakistan-based agency quoted the witnesses as saying that the rockets landed in wasteland, causing no casualties.

Another AIP report quoted sources as saying that two rockets were fired at the special forces base some three miles east of the nearby town of Gardez.

It said one was fired early in the morning and the second a few hours later.

They fell in the vicinity of the base, but caused no casualties.

FIREFIGHT EARLIER IN WEEK

The U.S. military said earlier this week that a brief fire fight had erupted between U.S. forces and some Afghans on Sunday after tracer fire was directed at the Chapman Air Field in Khost.

Khost has been the scene of clashes this week between government forces and renegade warlord Padshah Khan Zadran.

In Kabul, peacekeepers from the International Security Assistance Force said they were on high alert but had received no specific threats and were patrolling the capital as normal.

Kabul was the scene last Thursday of a major car bomb attack which killed 26 people and wounded many more. The same day, President Hamid Karzai survived an assassination attempt in the southern city of Kandahar.

On Monday, U.S. officials said hundreds of U.S. troops had launched a major operation in eastern Afghanistan near the Pakistani border in search of al Qaeda remnants. They said the operation, involving soldiers of the 82nd Airborne Division, was in the Bermal Valley in Paktika province near the village of Shkin.

The region has easy transport links to the Waziristan region of western Pakistan, where many al Qaeda fighters are thought to have taken refuge.

The operation, codenamed "Champion Strike," is aimed at killing or capturing al Qaeda members and denying them the ability to operate in the area, the U.S. military said.

It was the latest in a series of U.S.-led missions in the east and southeast of Afghanistan, which have yielded many stockpiles of old weapons, but only a small number of arrests.

The whereabouts of both bin Laden and Taliban leader Mullah Omar remain unknown.

U.S. bases have come under occasional attack, usually by rocket fire but these have caused few if any casualties.

About 40 U.S. soldiers have been killed in combat and non-combat incidents in Afghanistan in the past year, while U.S. forces are thought to have killed thousands of Taliban and al Qaeda fighters as well as hundreds of civilians.

PHOTO CAPTION

A U.S. Air Force guides a pilot in his A-10 Thunderbolt attack jet on to the flight line at the air base in Bagram, Afghanistan, Wednesday, Sept. 11, 2002, the first anniversary of the terror attacks in the United States. (AP Photo/Wally Santana)