Two Jaish-e-Mohammed militants were suspected to have sneaked into the national capital and were planning high profile attacks, including taking hostages, following which security was today stepped up in the city, a day after the Pathankot air base strike by the same Pakistan- based outfit.

Delhi Police received specific intelligence input about the presence of militants. Police Commissioner B S Bassi today held a meeting with its top brass and the department sought help of central paramilitary forces in providing security, especially around vital installations in the city, said a senior police official.

"We have inputs regarding two Jaish-e-Mohammed key members who have sneaked into Delhi and are suspected to be planning high profile attacks or hostage crisis.

"We have also got a few additional companies of paramilitary forces to increase security following the alert," said the official.

The national capital was already put on high alert yesterday in the wake of the Pathankot attack. Security was significantly heightened at the airport, railway stations, bus stands and other vital installations in the city.

Vigil was also heightened in several areas, including popular market places, in South Delhi, Central Delhi and the VIP movement zone in Lutyens' Delhi, a senior police official said.

Sleuths of Crime Branch and special cell of Delhi Police were also roped in and the security unit has been asked to form a strategy in connection with potential threats to VIPs in the national capital, the official said.

Earlier in the day, the Delhi-Lucknow Shatabdi was halted for searches at Ghaziabad and movement of several other trains disrupted after Northern Railways was alerted about a possible bomb threat to trains plying between Delhi and Kanpur.

"We received a call from the railway control room in the morning in which they said that they had received information about a potential bomb threat on a train plying between Delhi and Kanpur," a senior police official said.

A search operation was launched across all railway stations in the city covering all trains on the said route, the official added.