Baku, October 4 (AZERTAC). Militants have attacked a depot in Pakistan, destroying 27 tankers which were carrying fuel for Nato troops in Afghanistan.

The Taliban in Pakistan said it was behind the assault on the depot near Islamabad in which three people died, BBC reported.

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.

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."

The soldiers were killed when Nato helicopters strayed into Pakistani territory while chasing Taliban militants from Afghanistan.

Pakistan`s President Ali Asif Zardari said the cross-border incident was "counter-productive and unacceptable".

Mr Rasmussen added that he had called for the border crossing to be reopened as soon as possible and said the foreign minister had committed himself to work on the issue.

The BBC`s Nick Childs says the Nato secretary general`s meeting with the Pakistani foreign minister is a measure of the concern that both sides have about recent developments, and the latest attack only adds to the pressures.

The attackers stormed the depot where dozens of tankers were being prepared for a Nato convoy near Rawat outside Islamabad just after midnight local.

Local police said three people had died and another nine people were wounded.

A survivor said the drivers fled when the shooting started. Afterwards, the gunmen simply walked away, according to witnesses.

It is the second time Nato convoys have been attacked in recent days.

On Friday, at least 27 lorries carrying supplies for Nato troops were set on fire in the southern Sindh province.

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.

More than 200 lorries carrying supplies for Nato troops remain stranded at the border post.

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 which travel through Pakistan from the port of Karachi.

Nato supplies come under regular attack in Pakistan and 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 Khyber Pass is seen as a key lifeline for Nato supplies, although another route further south at Chaman has remained open.

A senior Pakistani spokesman said he hoped and expected that it would not take very long before Nato traffic was allowed through the Khyber Pass again, but he said it depended on the security situation.

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.