In a threat to Indian security along the LoC, Pakistan troops violated ceasefire twice in North Kashmir, killing four soldiers Thursday, reported DNA.

In retaliation to the firing, one Indian Junior Commissioned Officer (JCO) and three Pakistani soldiers were killed in first major violation of ceasefire in Kashmir valley this year, when troops from both the sides traded heavy gunfire, officials said.

The firing took place in North Kashmir, a key Keran sector, which is the major entrance route of the militants across the border. Millitants come on the heels in their infiltration bid from the adjacent Gurez sector also.

"There were two ceasefire violations in Keran sector of Kupwara district across the LoC since 2000 hours Wednesday," said Defense spokesman Lt Colonel J S Brar.

The JCO, who was badly injured in the retaliation, succumb to injuries after some time.

Army officials identified the JCO as Naib Subedar Gurdayal Singh.

Meanwhile, the Pakistani authority has another version of the incident saying that Indian forces had started firing.

Speaking to Geo news, Pakistan Army spokesman Major General Athar Abbas in Islamabad said that three Pakistani soldiers were killed in the gunbattle and claimed that Indian forces had fired across the border "unprovoked".

In opposition to India's allegation that the firing was started by Pakistani troops, Abbas identified the soldiers as belonging to irregular Mujahid battalion.

 "The soldiers had been moving between forward posts when they got lost in bad weather in the Neelam valley," said Abbas.

In the meantime Pakistan army has initiated a meeting with local Indian commanders to investigate the violation.

Indian military authority has countered Pakistan army's claim, saying that there was no ceasefire violation from Indian side.

"There was an infiltration bid by militants in Keran sector which was foiled by our troops. We lost one JCO in the operation," Brar said.

According to the Indian army, the Pakistani troops twice violated the ceasefire by shelling forward posts.

The first ceasefire violation took place at 2000 hours yesterday and the firing from other side of LoC continued for nearly 50 minutes.

The second ceasefire violation began at 1100 hours today and the exchange of fire was continuing till last reports came in, he said.

Pakistani troops stationed at Saheli post opened unprovoked firing at Shalapathri post on Indian side of LoC, leaving a soldier injured.

The sources said the ceasefire violations from Pakistani side were apparently aimed at giving cover to militants trying to infiltrate into Kashmir ahead of snowfall which will close all passes along the rugged terrain of LoC.

The ceasefire violation along the LoC needs to check, 44 cases of ceasefire violations were reported in 2010 where as in 2009 it was 28 and 77 in 2008.