Taliban insurgents including a suicide bomber in a truck killed six people in an attack on a foreign logistics and supply company in Kabul on Tuesday, police said, the latest in a string of daring assaults in the Afghan capital.
The Taliban claimed responsibility for the early morning attack in an area in the north of Kabul used by a number of foreign companies supplying NATO forces in Afghanistan.
Violence is escalating across Afghanistan as NATO-led combat troops prepare to leave by the end of 2014.
Kabul police chief General Ayoub Salangi said two truck drivers working for the foreign logistics company and four Nepalese guards were killed in the attack. Three other employees were wounded, he said.
The attack began when one of the insurgents drove an explosives-laden truck into a vehicle bay in the compound north of Kabul airport, detonating an explosion that left a crater six metres (20 feet) deep and about 15 metres wide.
"It made a hole the size of a pool," Salangi said.
Three other attackers then engaged in a gunfight with Afghan security forces for up to an hour before they were killed, Salangi said. Three vests packed with explosives were recovered from the scene, he said.
A Reuters witness said he saw the bodies of two people being carried away, although it was not clear if they were those of the attackers or of other victims.
Atiqullah, a 54-year-old truck driver for the company, said at least four co-workers had been wounded in the attack.
"I woke up to go for morning prayer and suddenly there was a very heavy explosion followed by gunfire," said Atiqullah, who uses only one name.
"We escaped from the compound and went to another company nearby. Security forces came in 30 minutes and rescued us," he said.
The Taliban, in an emailed statement from spokesman Zabihullah Mujahid, claimed responsibility for the attack and said its fighters had entered what it described as "an important foreign base and logistics warehouse".
The Islamist group routinely exaggerates the impact of such attacks.
It was the latest in a series of high-profile assaults by insurgents in Kabul.
It came a week after Taliban fighters managed to penetrate the most secure area of Kabul and attack buildings in an area that includes the palace of Afghan President Hamid Karzai.
On Monday, Afghanistan's main intelligence agency, the National Directorate of Security (NDS), said they had arrested a man in Kabul carrying a suicide vest and an automatic rifle who had planned to attack one of their compounds.
Another would-be suicide attacker, a Pakistani citizen, was also arrested in the eastern Afghan city of Jalalabad on Monday, police said.