Security has been tightened in and around Delhi following intelligence about four Pakistan-based Jaish-e-Mohammad terrorists having entered the capital to strike during the festival season as revenge for Kashmir, home ministry officials said on Thursday.

All the airports in the country have been put on “red alert”, they added.

A meeting attended by the Union home secretary and top security officials at Prime Minister Narendra Modi’s residence discussed the threat on Thursday morning, a ministry official said.

He said Delhi police’s special cell had received an alert on Wednesday evening about the presence of the four terrorists in Delhi. They are said to be heavily armed.

“Security agencies, including the Delhi police, are working on the intelligence. Raids by the Delhi police’s special cell are on to nab the terrorists,” the official said.

Over the past few weeks, the security agencies have received multiple intelligence inputs about possible terror attacks in retaliation to the government’s decision to strip Jammu and Kashmir of its special status and split it into two Union Territories.

Jaish has apparently been plotting suicide attacks in Delhi and some other places, including air force bases.

An Intelligence Bureau official confirmed that security had been stepped up in and around Delhi.

“Patrolling has been intensified and police pickets have been put up across the capital as the city gears up for Durga Puja and Ramlila,” he said.

“Air force bases in and around Jammu and Kashmir and Punjab have also been put on alert. Security has been beefed up at the airbases in Amritsar, Pathankot and Srinagar.”