Over 70 people,including 28 security personnel,were killed when hundreds of heavily armed Taliban fighters crossed into northwest Pakistan and besieged a remote checkpost,in one of the deadliest attacks in months. About 300 heavily armed militants attacked the check post at Shalotal in Upper Dir district of Khyber-Pakhtunkhwa province early yesterday. Intermittent gun battles between the militants and troops continued till today. Officials today said 27 security personnel had died so far and efforts were underway to evacuate the bodies. They claimed 45 militants were killed though this could not be independently confirmed. Six civilians,including two women and as many children,were also reportedly killed during the clashes. The check post attacked by the militants is located close to the border with Kunar province of Afghanistan. Officials said the militants had destroyed two schools and several houses with rockets. The local administration rushed additional policemen and Frontier Constabulary troops to the area to flush out the militants. Helicopter gunships pounded locations where the militants were holed up. The administration imposed curfew in the area and sealed it off. The army had conducted a major operation against the Taliban in Dir and nearby areas two years ago. At least 13 Pakistani security personnel were killed in a similar cross-border raid by Taliban in the Lower Dir region two months ago. In a late night development,Foreign Secretary Salman Bashir conveyed to the Afghan Ambassador Pakistan's " strong concern on the cross-border attack launched from the territory of Afghanistan in Dir by some 300-400 militants." The militants had attacked villages and burnt schools,Bashir was quoted as saying in a statement issued by the Foreign Office. Bashir "stressed the need for stern action by the Afghan Army,US and NATO-ISAF forces in the area against militants and their hideouts in Afghanistan and against organisational support for the militants." Pakistan's concerns were also brought to the attention of the US and NATO,the statement said.