Pakistan’s security forces have arrested a senior Afghan Taleban commander in the southwestern Pakistani city of Quetta, according to British officials, who hailed it as a significant breakthrough yesterday. Mullah Rahim, the most senior Taleban leader in Helmand province, gave himself up on Saturday, a statement from British Forces in Afghanistan said.

The US and Britain have often complained that Pakistan is not doing enough to arrest or kill top Taleban leaders who are sheltering in Quetta, the capital of Baluchistan, or its lawless northern tribal areas.

That, combined with a build-up of Nato troops near the Afghan border, has sparked fears among Pakistani officials that Nato troops might launch a unilateral strike on Taleban positions inside Pakistan.

Pakistan has opposed any such action on the grounds that it would violate its sovereignty, enrage its mainly Muslim population and escalate an internal conflict in the ethnic Pashtun borderlands.

The issue is so sensitive that Pakistani security officials would neither confirm nor deny the capture of Mullah Rahim — just as they have never acknowledged the arrest of other high-ranking insurgents in the past.

Tony Cousins, a spokesman for British Forces in Helmand, called it a breakthrough and said that it would not affect the fighting capability of the Taleban immediately but that it would impair their long-term strategic planning.

“He obviously felt the net closing in around him and decided to give himself up,” he told The Times. “This is going to cause major problems for the Taleban. They’ve got gaps to fill and no one to fill those gaps.”

The British statement also said that a missile strike just after midnight on Sunday killed Abdul Rasaq, a Taleban leader who led fighters in the Musa Qala area of Helmand province.

Rasaq, also known as Mullah Sheikh, was the third senior Taleban leader whom British Forces claim to have killed in recent months. The other two were Bishmullah, a key Taleban strategist killed on July 12, and Sadiqullah, a planner and bomb-maker killed in June.

Gulab Mangal, the governor of Helmand, said that the death of Rasaq was good news for his province — the centre of the opium trade and the Taleban insurgency in Afghanistan.

“I advise all those Taleban who are engaging with terrorist actions that the fighting has no benefits,” Mr Mangal said.

The Afghan Defence Ministry announced in December that Mullah Rahim Akhond, the Taleban governor for Helmand, and Mullah Mateen Akhond, the district governor in Musa Qala, had been caught.

The precise command structure and strength of the Taleban remains unclear, according to British military officials. The Islamic movement’s

Government was toppled by a US-led invasion in 2001 but it has regrouped and started a fierce insurgency since British Forces deployed in Helmand in 2006.

British Forces suffered their 111th atality in Afghanistan on Tuesday when militants hit a patrol in southern Helmand, killing one soldier and injuring two others, the Ministry of Defence announced yesterday. The soldier, who was killed by a roadside bomb, was from the Royal Electrical and Mechanical Engineers, attached to 2nd Battalion The Parachute Regiment.

Pakistan said that it has hunted for al-Qaeda fighters near the Afghan border and is locked in an increasingly intense conflict with Pakistani Taleban fighters in the region.

It has been less forthcoming with Afghan Taleban leaders — either because of a lack of reliable information, or because of enduring links between the movement and the Inter-Services Intelligence Agency of Pakistan.

There have been signs of progress, however. In February Mullah Mansour Dadullah, a commander who had been dismissed by Mullah Omar, was caught in Baluchistan. In March last year Pakistani security forces in Quetta arrested Mullah Obaidullah Akhund, a former Taleban defence minister and the third most senior member of its leadership council.

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