Islamabad, Aug 28 (DPA) At least 28 people were killed Thursday in a suicide bombing and a missile attack carried out by a US pilotless aircraft in Pakistan's troubled northwest region, government officials said.

A suicide bomber struck at a Pakistani security post on the border with Afghanistan when members of tribal police, known locally as the Khasadar force, gathered at the Torkham border checkpoint in the north-western tribal district of Khyber for an iftar, a meal to break the daily fast during the Muslim month of Ramadan.

'The initial reports show that a suicide bomber, apparently a young man, who was carrying bottles of mineral water, approached on foot and blew himself up,' said Tariq Hayat Khan, the top government official in the district.

At least 22 people were killed. Security officials recovered the charred body of the suspected suicide attacker.

The Torkham border crossing is on the main land route used to ferry almost 75 percent of the fuel, food and military supplies to NATO forces from Pakistan's port of Karachi to Afghanistan.

Taliban militants have attacked NATO supply convoys, disrupting supplies several times this year.