Pakistan today summoned Indian ambassador Sharat Sabharwal to protest against alleged "unacceptable and unprovoked" attacks by the Indian army that killed two Pakistani soldiers in five days in Kashmir.
Pakistan said its soldiers were killed on Sunday and Thursday.
India said two of its soldiers were killed by Pakistani troops and that one of them was beheaded along the LoC.
Pakistan's foreign ministry said it had summoned India's high commissioner to Islamabad to lodge a "strong protest on the repeated, unacceptable and unprovoked attacks on Pakistani soldiers by the Indian army".
India said its troops opened fire in response to Pakistani fire on both occasions. Pakistan has denied any responsibility for the Indian soldiers' deaths.
On Friday, Pakistan called on the Indian government to investigate the "repeated" violations of the ceasefire, which has held along the Line of Control (LoC) since 2003 and to take steps to prevent them from happening again.
Both countries have appeared determined to prevent the recent killings from wrecking a fragile peace process, which resumed in 2011.
Islamabad repeated an offer to hold an independent inquiry through the United Nations and reiterated its commitment to peace talks with India, saying the attacks "create unnecessary and avoidable distractions" to peace efforts.
On the ground, more than 300 people demonstrated in Pakistan occupied Kashmir on Friday, condemning Indian aggression and accusing Indian troops of ceasefire violations, police said.
The crowd condemned the killings of Pakistan soldiers in the state capital Muzaffarabad and dispersed peacefully, local police chief Raja Shafqat told AFP.
The rally was also attended by state premier Chaudhry Abdul Majeed, who accused New Delhi of deliberately disturbing peace in the region and said further protests would be held on Monday.
The United States has urged the nuclear-armed rivals to cool tensions along the heavily militarised LoC.