A gas pipeline in south-western Pakistan has been attacked for the third time in a week, again severely disrupting supplies.

Two pipelines near Sui in Balochistan province, 700 kilometres (435 miles) south-west of Islamabad, were struck on Sunday night.

We expect gas supplies to be normal within the next 24 to 36 hours Gas company official

Some reports said it was another rocket attack, others that explosives were used.

Feuding local tribesman were again thought to be behind the attack.

Supplies from both pipelines - to Punjab and North-West Frontier provinces - were hit.

Set ablaze

About 2.2 million customers in the same provinces suffered severe gas shortages following attacks on the pipelines at Dera Bugti, near Sui, last Tuesday and Wednesday.

As with last week's attacks, supplies on Monday were immediately suspended for industrial users and reduced for domestic customers.

Sunday's attack set the pipelines ablaze again, with flames visible several miles away.

No casualties were reported and again no one has claimed responsibility.

The Sui gas fields - Pakistan's largest - are operated by Sui Northern Gas Pipelines.

One company official, Saifuddin, said: "Our teams of engineers are there and repair has already begun. We expect gas supplies to be normal within the next 24 to 36 hours."

Security stepped up

The fields are located in an area where Bugti and Mazari tribesmen have been waging a bitter and protracted feud.

An inquiry by the gas company into last week's attacks concluded that they were acts of sabotage.

Many drivers were unable to get compressed gas

Samiullah Abid, a government official in the area, said security had been stepped up but that it was impossible to prevent attacks.

Last week's cut in supplies left millions of Pakistanis unable to cook or heat their homes.

Many drivers could not obtain compressed gas fuel for their cars.

Officials said they had repaired the damage and resumed supplies on Thursday.

But one of the pipelines began leaking and supplies were only fully restored on Saturday.

The situation was made worse by a cold snap that has struck much of Pakistan and other parts of South Asia since Christmas.