Miranshah, Pakistan: Mortar shells fired from across the border in Afghanistan hit a Pakistan military border post killing four soldiers, Pakistan security officials said Tuesday.

Two other soldiers were wounded in the attack in South Waziristan tribal district, they said, in the latest in a series of deadly cross-border incidents that have raised tensions between the neighbouring countries.

"Four soldiers were killed and two others were wounded in this cross-border attack," a senior security official in Peshawar told Agencies.

"More than 20 mortar shells were fired from across the border. Three shells slammed into a paramilitary Frontier Corps checkpost in Angoor Adda area," he added.

Another security official in Wana, the main town of South Waziristan tribal district, confirmed the incident and casualties. Both the officials blamed the Afghan National Army (ANA) for the attack.