JAMRUD: A suicide bomber killed 22 Pakistani border guards on Thursday in an attack at the main crossing point into Afghanistan, government officials said.

It was the first big attack in Pakistan since Pakistani Taleban chief Baitullah Mehsud was killed in a US missile strike on Aug. 5 and will raise fears that the militants, who officials say have been in disarray, are hitting back.

The bomber struck as the guards were preparing to break their fast in the evening.

“The guards were about to break their fast when a teenage boy carrying a bottle of Pepsi walked toward them and blew himself up,” said Wakil Khan, a witness at the Torkham border crossing.

Nasir Khan, a senior government official in the Khyber region, said 22 people were killed.

Pakistan has been hit by a series of suicide bomb attacks over the past two years, launched by Al-Qaeda-linked militants fighting the government because of its support for the US-led campaign against militants.

Security forces have cleared most militants from the Swat Valley, northwest of Islamabad, in an offensive since late April, and have also been attacking Mehsud’s men in the South Waziristan region on the Afghan border.

Prime Minister Yousaf Raza Gilani said in a statement the attack at Torkham was a cowardly act and his government was determined to stamp out terrorism.

Earlier on Thursday, two missiles believed to have been fired by a US drone struck a militant hide-out killing six fighters in South Waziristan, intelligence officials said. The Taleban had been denying Mehsud’s death for weeks, but on Monday two of his aides, Hakimullah Mehsud and Wali-ur-Rehman, confirmed their leader had been killed. Security officials have been saying they were expecting reprisal attacks by Hakimullah’s men and Thursday’s blast in Khyber would appear to indicate he is determined to press on with the fight against the government.

Torkham is at the top of the Khyber Pass, through which a large amount of supplies for Western forces in Afghanistan, including much of their fuel, pass into landlocked Afghanistan.

Hakimullah’s men stepped up attacks on convoys trucking supplies through the pass early this year, forcing the United States and its allies to look for new routes into Afghanistan, but their raids have fallen off in recent months.