Pakistan accused Indian troops of killing a civilian and wounding two others in "unprovoked firing" across the border Saturday as New Delhi voiced "grave concern" about the new military flare-up in disputed Kashmir.
The Himalayan region of Kashmir has been the spark of two of three wars fought by nuclear-armed India and Pakistan since their independence from Britain in 1947.
In Islamabad, a Pakistani military official said a civilian was killed and two others injured by "unprovoked firing of heavy weapons including mortars by Indian Border Security Forces" near the eastern city of Sialkot in eastern Punjab province.
On Thursday, Pakistan accused India of killing a paramilitary soldier in "unprovoked firing" across the border in the same region.
Indian foreign minister Salman Khurshid in New Delhi described the military flare-up as a "serious matter."
"This is a serious matter, a matter of great concern to India," Khurshid told India's NDTV channel as the Press Trust of India said two paramilitary soldiers of the Border Security Force (BSF) were hurt in overnight Friday attacks by Pakistani troops.
BSF troops "retaliated strongly", the national news agency report said, and added the attack was the latest in a string of five violations in the past 24 hours of a 2003 truce along Kashmir's disputed border.
"We will handle it (the new flare-up) with the greatest sagacity, greatest firmness and determination to protect both the sovereignty and the safety and security of our citizens," the Indian foreign minister said.
The clashes follow a pledge a few weeks ago by the prime ministers of the two countries at a meeting on the sidelines of a UN conference to restore calm along the Line of Control (LoC), the heavily militarised de facto border dividing Kashmir.
A spike in fighting along the LoC in January stalled peace talks which had only just resumed following a three-year hiatus sparked by the 2008 attacks in Mumbai that killed 166 people.
More violence erupted along the LoC after five Indian soldiers were killed in a raid in August.
Delhi blamed that ambush on the Pakistan army, but Islamabad denied the claims and has repeatedly called for restraint and dialogue.