Prime Minister Dr. Manmohan Singh today took stock of country's comprehensive security scenario with the military top brass in New Delhi. At the meeting, the armed forces' preparedness to meet any security challenge that may be posed by terror networks in the region and conventional threats from Pakistan's armed forces came up for review. According to defence sources, the Prime Minister was briefed on the overall security measures and the general preparedness of the defence forces. Issues like changing security situation in Pakistan and the situation along the Sino-Indian border were also discussed. The 90-minute security review at the Prime Minister's residence was attended by Defence Minister A K Antony, National Security Adviser Shiv Shankar Menon, the three service chiefs, Defence Secretary Pradeep Kumar and DRDO Chief V K Saraswat.Our correspondent reports, last Wednesday Defence Minister A.K. Antony held a similar two-day review of overall security of the country and coastal security in particular with maritime agencies .The Prime Minister's review comes two days after he returned from Kabul, where he had discussed the latest post Osama developments in the region with Afghanistan President Hamid Karzai.The Indian Army has also raised its alertness level in the wake of reports that Pakistan may try to infiltrate militants into Jammu and Kashmir. It has also raised an alarm over Chinese military personnel's presence in Pakistani Kashmir in the guise of engineering workers and the threat posed by the large neighbour to the security of Jammu and Kashmir.