The head of the Pakistani Army’s medical corps today became the most senior officer to be killed since the country pledged its allegiance to the US after the attacks on September 11, 2001.

Lieutenant General Mushtaq Baig, the army’s surgeon-general, died when a teenage suicide bomber blew himself up next to a convoy on a busy road in Rawalpindi, a garrison city and the scene of a string of recent attacks including the assassination of Benazir Bhutto, the former Prime Minister.

Meanwhile, in another day of instability in Pakistan, unidentified gunmen opened fire and lobbed a grenade in the Mansehra offices of a British-run aid agency in the country's troubled north-west, killing four and wounding nine.

Speaking after the attack in Rawalpindi, Major General Athar Abbas, the military’s chief spokesman, said that the surgeon general, his driver and guard had been "martyred." The attack also claimed the lives of five civilians and wounded some 25 others.

“This was the first suicide attack in Pakistan in which a high-ranking military official has been killed since 9/11 and also the first attack after the election,” Mr Abbas noted.

Mohammedmian Soomro, who was appointed caretaker prime minister in the run-up to the country’s recent elections, blamed the bombing on “extremist elements”.

The perpetrators were “damaging the cause of Islam as a religion of peace, and also spoiling the national image of the country,” he added.

Pakistan has been battling Islamic militants in its tribal regions since President Pervez Musharraf allied himself with the United States ahead of its invasion of Afghanistan in 2001. However, the violence has intensified following a bloody government siege on Islamist militants holed up in Islamabad’s hardline Red Mosque in July 2007, during which over 100 people were killed.

Witnesses to today’s blast in central Rawalpindi, home to the army, spoke of bodies lying in the road amid the wreckage of the general’s black car and other nearby vehicles. Ambulances raced to the scene while security officals sealed off the area to allow bomb squad experts to comb for evidence.

“I can see pieces of flesh littering the road and four damaged vehicles,” an onlooker said.

The general’s black car was completely destroyed in the attack, while several other vehicles were also badly damaged. The bomber, who approached the convoy on foot, was believed to have been between 15 and 18 years old.

“There was a suicide bomber, he was perhaps waiting near the traffic light. He came close to the general’s car and exploded himself next to him,” Brigadier Javed Cheema Cheema, spokesman for the Interior Ministry, told Dawn Television.

“Parts of the bomber’s body including his legs have been found.”

Meanwhile in Mansehra, officials reported that a gang of armed men had stormed the offices of Plan International, a development agency based in Woking, southern England. Police said the men had arrived in two cars and fired shots before throwing a grenade into the offices and fleeing.

Hospital workers said two people had been killed at the scene, while a further two had died in hospital. Rizwan Shah, a doctor, said that one of the bodies had bullet wounds while another, a woman, had probably been killed by the explosion but was "badly charred" in the blaze which followed.

The charity said that all four killed were local workers and that there had been no foreign staff present in the office at the time. In a statement, it spoke of its shock at the attack in an area where it had worked for many years.

Tom Miller, Plan's chief executive, said: “Our primary concern is for our staff and the families of those hurt in the attack. We have immediately closed our operations across Pakistan and dispatched a security team to the area.”

The attacks come one week after parliamentary elections in which candidates allied to Mr Musharraf were routed by opposition parties. The vote had been delayed from early January following the killing of Ms Bhutto, which has been blamed, along with a string of subsequent attacks, on Baitullah Mehsud, a tribal warlord linked to al-Qaeda.

The largely peaceful polls had given fresh hope that a new government might be able to rein in militants, who yesterday said they were ready for peace talks if the military campaign against them was called off.

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