NEW DELHI - Unlike PM Nawaz Sharif who, in his Independence Day speech, vowed restraint in dealing with India, his Indian counterpart PM Manmohan Singh minced no words in his address Thursday to warn Pakistan against “anti-India activity”.

"India has always strived for friendship with its neighbouring countries," Singh said in an annual address marking India's 1947 independence from Britain delivered from the ramparts of the Red Fort in New Delhi.

"However, for relations with Pakistan to improve, it is essential they prevent the use of their territory and territory under their control for any anti-India activity," Singh said.

The Congress prime minister spoke from a bullet-proof enclosure at the Red Fort, which had been turned into a virtual fortress with tens of thousands of security forces guarding against a possible militant strike.

India blamed the killing of five of its soldiers in Occupied Kashmir last week on the Pakistan army and the incident has fuelled tensions between the neighbours. The Indian leader condemned the attack as "dastardly" and said New Delhi would "take all possible steps to prevent" future such incidents.

Islamabad has vociferously denied involvement of its soldiers in last week's ambush, one of the deadliest in years targeting Indian troops in the Muslim-majority region. It has accused India of continued violation of ceasefire by opening sporadic fire on its areas along the LoC which has so far killed at least two civilians and injured others.

India's army accused Pakistan troops of injuring three Indian soldiers in Thursday's firing between the two armies along the Line of Control, as intermittent firing continued along this heavily militarised ceasefire line dividing Kashmir. Kashmir has been the trigger of two of the three wars between the nations.

Pakistan's new PM Nawaz Sharif pledged Wednesday to respond to the intensifying friction with "restraint and responsibility". He suggested enhanced diplomacy as the solution to this grave situation and hoped India would also defuse tension. But the renewed tensions have jeopardised plans for what the two governments hoped might be a breakthrough encounter between Singh and Nawaz.