Militants attack Nato tanker convoy in Pakistan
Militants in Pakistan have destroyed 27 tankers which were carrying fuel for Nato troops in Afghanistan.
The Taliban in Pakistan said it was behind the assault on a depot near Islamabad which left three people dead.
Pakistan has stopped Nato convoys crossing the Khyber Pass in response to a Nato air strike last week in which three Pakistani soldiers were killed.
Nato said on Monday it regretted the deaths but called for the crossing to be reopened.
Later on Monday, a US drone strike killed at least five militants in the town of Mir Ali in the troubled north-western Pakistani region of North Waziristan region, Pakistani intelligence officials said.
In the early hours of Monday morning, militants stormed the depot where dozens of tankers were being prepared for a Nato convoy near Rawat outside Islamabad.
"Between 10 and 12 men armed with automatic weapons stormed the depot from two sides," Umar Farooq, a senior Islamabad police official told local TV.
"They opened indiscriminate fire on the tankers, many of [which] ignited on the impact of the bullets."
Local police said three people had died and another nine were wounded.
A survivor said the drivers fled when the shooting started. Afterwards the gunmen simply walked away, according to witnesses.
The lorries attacked on Monday were due to travel along the Khyber Pass to the Torkham border crossing, which has been closed for five days because of the dispute between Pakistan and Nato.
The Pakistani soldiers whose deaths sparked the dispute were killed on Thursday when Nato helicopters strayed into Pakistani territory while chasing Taliban militants from Afghanistan.
Pakistani officials said a military checkpoint had been hit while Nato said the helicopter crew had opened fire in self-defence.
Pakistan's President Ali Asif Zardari condemned the cross-border incident as "unacceptable" and the key border crossing was closed for supplies.
On Monday, after a meeting in Brussels with Pakistani Foreign Minister Shah Mehmood Qureshi, Nato Secretary General Anders Fogh Rasmussen said: "I expressed condolences to the families. Obviously this incident was unintended."
He called for the border crossing to be reopened as soon as possible and said Mr Qureshi had agreed to work on the issue.
The BBC's Nick Childs says the meeting between the two men is a measure of the concern that both sides have about recent developments, and the latest attack only adds to the pressures.
The border closure has left lorries and tankers open to attack at various points along the supply route from the port city of Karachi.
On Friday, at least 27 lorries carrying supplies for Nato troops were set on fire in the southern Sindh province.
More than 200 lorries carrying supplies for Nato troops remain stranded at the border post.
In a separate incident, another two Nato lorries were set on fire and a man was killed in southern Pakistan.
A Taliban spokesman told the AP news agency that the attacks would continue until the supplies had completely stopped.
He added that a new wing of the group had been set up to focus on the convoys.
Nato supplies have little or no security. Islamabad police chief Kalim Imam said the entire supply operation was "very vulnerable" to such attacks and it was impossible to provide constant protection.
The Nato-led International Security Assistance Force said on Monday that its operations were so far unaffected by the attacks but that it was "beginning to explore other options".
Supplies are currently brought into northern Afghanistan via Uzbekistan and Tajikistan but the spokesman declined to say which northern route was being considered.
Our correspondent says that Nato is playing down the logistical impact of the attacks for now, but if attacks on this scale become sustained, they will begin to have an effect.