Afghan CIA bomber 'was courted as potential informant'

The suicide bomber who killed seven CIA agents in Afghanistan had been courted by the US as a possible informant, US intelligence sources have said.

They said he had not undergone the usual full body search before entering the base in Khost province, and so was able to smuggle in an explosive belt.

The attack was the worst against US intelligence officials since the US embassy in Beirut was bombed in 1983.

US President Barack Obama has praised the work of those killed in a letter.

Paying tribute to the fallen, Mr Obama said those killed were "part of a long line of patriots who have made great sacrifices for their fellow citizens, and for our way of life".

He told CIA employees in a letter that the victims had "taken great risks to protect our country" and that their sacrifices had "sometimes been unknown to your fellow citizens, your friends, and even your families".

Claim questioned

From the moment the bomb was detonated inside the base on Wednesday, says the BBC's Peter Greste in Kabul, questions were raised about how he managed to pass through security.

But now intelligence sources familiar with the investigation have said that CIA agents working from Forward Operating Base Chapman had been attempting to recruit the man as a potential informant.

A US official, and former CIA employee, said such people were often not required to go through full security checks in order to help gain their trust.

"When you're trying to build a rapport and literally ask them to risk [their lives] for you, you've got a lot to do to build their trust," he told the Associated Press news agency.

The Taliban have said one of their members carried out the attack.

Spokesman Zabiullah Mujahid told the BBC the Khost bomber was wearing an army uniform when he managed to breach security at the base, detonating his explosives belt in the gym.

However, this claim was denied by the Afghan defence ministry.

"This is the Taliban talking and nothing the Taliban says should be believed," said ministry spokesman Zahir Azimi.

Neither the names of the CIA officials killed nor the details of their work have been released because of the sensitivity of US operations, the agency said.

But the head of the base - who was reported to be a mother of three - was said to be among the dead.

As chief, she would have led intelligence-gathering operations in Khost, a hotbed of Taliban activity due to its proximity to Pakistan's lawless tribal region.

'Great sacrifice'

CIA Director Leon Panetta said six other agents had been injured in the attack.

He said the dead and injured had been "far from home and close to the enemy".

"We owe them our deepest gratitude, and we pledge to them and their families that we will never cease fighting for the cause to which they dedicated their lives - a safer America," he said.

The flags at the CIA headquarters in Langley, Virginia, are being flown at half-mast in honour of the dead.

Forward Operating Base Chapman, a former Soviet military base, is used not only by the CIA but also by provincial reconstruction teams, which include both soldiers and civilians.

The airfield is reportedly used for US drone attacks on suspected militants in neighbouring Pakistan.

A total of 90 CIA employees have been honoured for their deaths in the agency's service since its inception in 1947, according to the Washington Post newspaper.

Pakistan volleyball crowd 'hit by suicide bomber'

At least 60 people have been killed after a suspected suicide bomb attack at a volleyball pitch in the troubled north-west of Pakistan, officials say.

Officials said the bomber drove a vehicle towards the field as people gathered to watch a match. Some sources suggest the death toll has reached 75.

The attack happened near Lakki Marwat, close to North and South Waziristan.

The Pakistani army has been conducting a campaign against the Taliban in the tribal areas since October.

Dozens of people were reported to be injured in Friday's attack. Several buildings collapsed, trapping people under rubble.

'Militant hub'

"The villagers were watching the match between the two village teams when the bomber rashly drove his double-cabin pick-up vehicle into them and blew it up," district police chief Mohammad Ayub Khan told AFP news agency.

Mr Khan told reporters the attack may have been in retaliation for attempts by locals to expel militants.

"The locality has been a hub of militants," he said.

"Locals set up a militia and expelled the militants from this area. This attack seems to be a reaction to their expulsion."

The BBC's Aleem Maqbool reports from Islamabad that among those killed are believed to be members of a local peace committee who have been campaigning for an end to the violence.

Mushtaq Marwat, a member of the group, told Pakistan's Geo TV that the attack occurred as the committee was meeting in a nearby mosque.

"Suddenly there was a huge blast. We went out and saw bodies and injured people everywhere," he said.

'Soft target'

Other witnesses recalled seeing a bright flash before hearing an ear-piercing explosion.

Some initial reports about the attack said the vehicle that exploded was stationary, or that a bomber had walked towards the volleyball pitch.

North and South Waziristan form a lethal militant belt from where insurgents have launched attacks across north-west Pakistan as well as into parts of eastern Afghanistan.

Our correspondent says it had been feared that while the army was congratulating itself on its campaign, militants had simply escaped to neighbouring areas such as the one where Friday's attack happened.

The number of people killed in militant attacks in Pakistan is fast approaching 600 in just three months, with no apparent end to the violence in sight, he adds.

Militants have attacked both "hard" targets, including army or intelligence offices, and "soft" ones such as markets or the crowd that was hit in Friday's bombing.

The attack came as a general strike was held in Karachi, Pakistan's commercial capital, in protest against a bombing there on Monday and riots that followed.

The bombing, which killed at least 43 people, targeted a Shia Muslim march and was claimed by the Taliban.

Afghanistan suicide bomber kills eight in Kandahar

A suicide bomber in a horse-drawn cart has killed eight people in the southern Afghan city of Kandahar, police say.

Police officers apparently tried to stop the bomber but he was able to detonate his explosives near a hotel and local government office.

Five of the dead were in a nearby car, with three pedestrians also killed. The care was destroyed, leading police to initially think the bomb was inside it.

Previous attacks in Kandahar province have been blamed on Taliban insurgents.

Security guards at the hotel became suspicious of the man and ordered him to stop.

Reports said he was fired on by the guards.

The target of the bombing was not immediately known, said deputy provincial police chief Fazel Ahmad Sharzad.