A U.S. general began a mission on Monday to help Afghanistan establish a national army with fighters loyal to the central government instead of the tribal leaders or local warlords.

The visit by Maj. Gen. Charles Campbell, chief of staff of the U.S. Central Command, is part of a plan to create a training program for the Afghan army, a military representative at the U.S. Embassy said.

U.S. soldiers are expected to arrive in about a month to begin training an Afghan force of about 600 men, the official said, speaking on condition of anonymity. The Afghan officers would go on to train future army units.

Since the fall of the Taliban, warlords have sought to extend their authority in several provinces. The cohesion of the government itself came into question last week when interim Prime Minister Hamid Karzai accused high-ranking officials within his own administration of assassinating the aviation and tourism minister.

Virtually every day brings a reminder that Afghanistan has a long way to go in its pursuit of peace.

Land- and sea-based planes launched airstrikes against enemy forces in eastern Afghanistan over the weekend after coalition forces were attacked while trying to pass a roadblock, U.S. officials confirmed.

And police in Pakistan found four rockets aimed at part of Karachi International Airport used by the U.S.-led coalition in Afghanistan. Waqar Mulan, an airport security official, said the Chinese-made rockets were equipped with homemade launchers and a timing device for automatic firing.

Police defused the rockets without incident.

Afghan authorities, meanwhile, disputed U.S. accounts of a firefight at the U.S.-controlled base at Kandahar last week, saying their inquiry shows American forces there probably never came under attack.

A U.S. spokesman at the base called the assertion "beyond belief." Two American soldiers suffered flesh wounds in Wednesday's heavy fire on the perimeter of the Kandahar base. U.S. troops told of coming under attack by intruders who worked their way to within 30 feet of foxholes.

Kandahar provincial authorities now suggest that rounds fired by mistake -- perhaps either by Afghans who patrol outside the perimeter, or by Americans themselves -- may have drawn U.S. fire.

"We are 90 to 95 percent sure the incident was not an attack on Americans ... it was a mistake," said Maj. Naik Mohammed, Afghan commander in this southern city.

In another development, an official in the former Taliban stronghold of Kandahar said rival tribal factions in neighboring Uruzgan province had agreed to mediation in the power struggle that he said played a part in a botched U.S. special forces raid Jan. 23.

Americans killed 21 men, including 19 who Afghan authorities say were on a government-sponsored mission to retrieve surrendered Taliban weapons.

Afghans widely believe Afghan informants delivered false accusations to the United States, helping prompt the American commandos' attack on the town of Khas Uruzgan.

"It was trouble between these two factions, that's why this whole ... raid happened," said Ahmed Wali Karzai, a Kandahar council member and brother of the interim prime minister. He is believed to work closely with U.S. special forces.

Men from both factions, meeting with him in Kandahar over the weekend, had agreed to his offer to provide mediation after the weekend's Eid Islamic holiday, Karzai said.

Meanwhile, Afghan officials aided by planes sent from Britain, Saudi Arabia and Pakistan scrambled Monday to take Islamic faithful to the annual pilgrimage in Mecca, Saudi Arabia. A lack of flights has blocked thousands from making the journey, stirring anxiety among people who paid for the trip but may not be able to go.

The urgency in moving pilgrims to Mecca was brought home after Afghanistan's aviation minister, Abdul Rahman, was killed at the Kabul airport last week during a riot among would-be pilgrims furious over flight delays to Saudi Arabia.

Karzai said senior officials, including the deputy intelligence chief, were behind the killing and vowed to punish them harshly. It wasn't clear if he was implying that the officials used the rioters as cover, or whether he thinks they incited the mob.

The government on Monday appointed a new aviation minister, Zalmay Rasoul, Afghan television announced.

Flights carrying pilgrims were leaving throughout the day Monday, with leased aircraft, a Pakistani plane and another four British C-130 Hercules ferrying people to Saudi Arabia, said Capt. Graham Chapman, a press officer for the peacekeepers.

The pilgrimage draws millions of people each year to Mecca, Islam's holiest site. Islam requires the journey at least once in a lifetime of every able-bodied Muslim who has the means to go.