(Recasts throughout, adds casualties, police chief, background)
KABUL, July 2 (Reuters) - Insurgents including a suicide bomber in a truck launched an attack on Tuesday in an area in the north of the Afghan capital used by foreign firms supplying NATO forces in Afghanistan, police said, the latest in a string of raids in Kabul.
Four employees of a foreign logistics and supply company were wounded in the attack, a driver for the company and a witness said. Police said at least two attackers were killed.
Kabul police chief General Ayoub Salangi said the early morning attack began when a suicide gunman drove a bomb-laden truck into a vehicle bay in a compound north of Kabul airport, triggering a loud explosion.
At least two other attackers then engaged in a brief gunfight with Afghan security forces before they were killed, Salangi said. Two suicide 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 attack on the logistics company was the latest in a series of high-profile assaults by insurgents in Kabul and comes amid escalating violence across Afghanistan as most foreign combat troops prepare to withdraw by the end of 2014.
It comes 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 arrested in the eastern Afghan city of Jalalabad also on Tuesday, police said. (Reporting by Mirwais Harooni and Omar Sobhani; Editing by Paul Tait)
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