Eighteen Shiite Muslims were killed and four injured on Saturday when Sunni militants opened fire on a vehicle convoy escorted by security forces in Pakistan's restive tribal region, officials said.
Gunmen attacked the two minibuses with assault rifles and rocket propelled grenades as the convoy was heading towards Peshawar, the capital of the north-western province of Khyber-Pakhtunkhwa, from Parachinar, the main town in Kurram tribal district.
"Six people died on the spot while 12 succumbed to their injuries when they were being transported to the hospital or at the hospital," said a health official at military-run hospital in Tull, a small town in the district of Hangu.
"Among the dead are also eight women and one child," said the official. "Two of the four injured are in critical condition."
Kurram, one of seven tribal districts located along the Afghan border, has a long history of armed clashes between Sunni and Shiite tribesmen. The fighting has intensified for the last two years as Sunni tribesmen are increasingly getting support from Taliban militants, who also follow Sunni Islam.
Heavily armed Sunni militants have besieged the Shiite-dominated areas, closing the Parachinar-Peshawar highway, the main road that links Shiite areas with the rest of the country.
The road closure has forced Shiite tribesmen to travel via the Afghan province of Paktika to reach Peshawar. But even that route is not safe.
At least 11 Shiites were killed last on Saturday when assailants opened fire at a bus travelling from Parachinar to Peshawar in the Afghan district of Samknai.