Terror Alert in India: Airports across north India have been placed on high alert.

Highlights Four Jaish terrorists have entered Delhi, planning strikes, warns intel

Special cell of Delhi Police received an alert on Monday evening: sources

Threat was discussed at a meeting at PM's residence

Four terrorists of the Pakistan-based Jaish-e-Mohammed have entered Delhi and are planning to strike during the festival season, inputs received by security agencies reveal. Airports across north India have been placed on high alert and security has been enhanced, say officials. Intelligence sources say a special cell of the Delhi Police received an alert last evening about the presence of the terrorists in the capital. All four are said to be heavily armed.

The alert led to searches across Delhi, especially in its more crowded neighbourhoods.

The threat was discussed at a meeting at Prime Minister Narendra Modi's home this morning.

We are on alert and taking all anti-terrorism measures. We are working on all inputs. There is nothing to worry," said MS Randhawa, Deputy Commissioner of Police (Central Delhi).

Security agencies have received inputs in recent weeks about attacks in retaliation against the government's decision to end special status to Jammu and Kashmir under Article 370 and split it into two union territories.

The country has been in a state of high alert after intel warnings of a terror plan to target PM Modi, Home Minister Amit Shah and National Security Adviser Ajit Doval. The home ministry put out an alert to all states following a threat naming 30 major cities. The Indian Air Force (IAF) is also alert to a threat to frontline bases following multi-agency inputs.

An "orange alert", which is a notch lower than the highest state of emergency, is in place at important installations and security has been tightened on IAF bases in Srinagar, Awantipora, Jammu, Pathankot and Hindon.

According to inputs received by the defence ministry and intelligence agencies, the Jaish-e-Mohammed has been plotting a fidayeen or suicide attack on air bases. The inputs include a threat letter dated 10 September, received by the Bureau of Civil Aviation Security. The letter in Hindi is reportedly from one Shamsher Wani of Jaish and claims revenge for the government's Article 370 decision.