More army personnel were deployed in the hills and dense forests of Jammu and Kashmir's Kathua-Udhampur-Doda belt as the search for the terrorists behind the ambush on an army patrol in Kathua district entered its fourth day on Thursday.

Since the attack on Monday, that killed five army personnel and injured as many, 60 people have been detained for questioning, including three individuals suspected of providing food and shelter to the terrorists, officials said.

One those detained is a woman who cooked food and handed over it to a person. The quantity of food prepared was sufficient for "10 to 15 people", they said. Security agencies suspect that the food was intended for the terrorists, the officials added.

In Kathua, senior police and Border Security Force officers from Jammu and Kashmir and Punjab met to discuss the security grid along the International Border (IB), from across which the terrorists are believed to have infiltrated, the officials said.

In the interstate security review meeting, discussions were held on devising a joint strategy for addressing cross-border infiltration along the Jammu and Kashmir and Punjab stretch of the IB and countering terrorist activities in the Jammu region, bordering Punjab, they said.

On the search operation, the officials said troops are moving with caution as there is a threat of Improvised Explosive Devices (IEDS).

The search has been expanded into the hilly areas of Kathua, Udhampur, and Doda districts of the Jammu region, that has seen a spate in terror incidents since June.

Troops from the army's 9 Corps have intensified their presence in the Kathua hills, while the Delta Force of the 16 Corps has moved in more personnel in the twin districts of Udhampur and Doda, focusing on areas like Seoj Dhar, historically a sanctuary for terrorists, particularly foreign militants, in 1990s.

This has been done to cordon the hilly areas so that the terrorists cannot escape, the officials said and added that the ground teams are being supported by surveillance data from unmanned ariel vehicles. Special forces and sniffer dog units of the army have been also deployed, they said.

These areas are characterized by dense forests, deep valleys, caves, and rugged terrain, with troops contending with adverse weather conditions such as rain and fog, the officials said.

Security measures have been increased to counter potential IED threats along highways and other sensitive areas, including the sites of the ongoing Amarnath yatra, they said.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.