With Pakistan plunging into turmoil, 'sleeper' terrorist cells in Jammu and Kashmir [Images] have been suddenly activated resulting in upsurge in violence in the state, Army said on Monday.

A high alert has also been sounded along the Line of Control by the army as it apprehends stepped up infiltration attempts and attacks by militants.

The terror attacks in Jammu and Kashmir have witnessed an upsurge lately, after remaining low for the last six months, Vice Chief of Army Staff Lt Gen M L Naidu told media persons in New Delhi.

He attributed the spurt in terrorist attacks in the state to 'sudden activation of sleeper terrorist cells' on directions from across the borders.

Noting that security forces were constantly monitoring the developments in the neighbouring country, Gen Naidu said, "In view of turmoil across the border, there are fears that there could be spurt in infiltration attempts."

He said army apprehended stepped up in attacks by foreign mercenaries in Jammu and Kashmir and security forces had been put on 'high alert' all along the 742 km-long Line of Control to check any infiltration attempts.

"We have put all army units on high alert along the LOC as well as sounded an alert to units engaged in counter insurgency," he said.

In addition, he said the BSF units posted along the International Border with Pakistan across Jammu sector were also on high alert.

For the past three days, Naidu said army units had neutralised three major attacks by suicide squads of the Lashkar-e-Tayiba in various parts of the valley and troops are on alert for more such attempts apprehended.

Troops had taken more time to destroy these squads, he told media persons, only because of strict instructions to avoid any collateral damage as these attacks had come in heavily populated areas.