New Delhi, Apr 23 (PTI) India on Wednesday downgraded diplomatic ties with Pakistan and announced a raft of measures, including expulsion of Pakistani military attaches, suspension of the Indus Water Treaty of 1960 and immediate shutting down of the Attari land-transit post in view of the cross-border links to the horrific Pahalgam terror attack that killed 26 civilians.

A day after the brazen attack, the Cabinet Committee on Security (CCS), under the chairmanship of Prime Minister Narendra Modi, firmed up five specific retaliatory measures against Pakistan, directed the security forces to maintain "high vigil" and vowed to bring the perpetrators of the crime to justice.

At a late evening media briefing, Foreign Secretary Vikram Misri, announcing the decisions, said the overall strength of the Pakistani and Indian high commissions will be brought down to 30 from the present 55 through further reductions, to be effected by May 1.

The foreign secretary said Pakistani nationals will not be permitted to travel to India under the SAARC visa exemption scheme (SVES) and any Pakistani national currently in India under it SVES visa has 48 hours to leave India.

Misri said the cross-border linkages to the Pahalgam attack were "brought out" in a briefing to the CCS following which it decided to take the measures against Pakistan.

The new retaliatory actions shut down the few existing diplomatic mechanisms between the two sides taking bilateral relations to yet another new low.

The foreign secretary, announcing the five retaliatory measures, said that "the defence, military, naval and air advisors in the Pakistani High Commission in New Delhi are declared persona non grata" and they have a week to leave India.

India will be withdrawing its own defence, navy and air advisors from the Indian High Commission in Islamabad, he said.

"These posts in the respective high commissions are deemed annulled. Five support staff of the service advisors will also be withdrawn from both high commissions," he said.

Pakistani nationals will not be permitted to travel to India under the SAARC Visa Exemption Scheme (SVES) and any such visas issued in the past to Pakistani nationals are deemed cancelled, Misri said.

The CCS was briefed in detail on the attack, in which 25 Indians and a Nepali citizen were killed, the foreign secretary who attended the meeting along with External Affairs Minister S Jaishankar, Defence Minister Rajnath Singh, Home Minister Amit Shah and NSA Ajit Doval, said.

The foreign secretary said the CCS resolved that the perpetrators of the Pahalgam attack would be brought to justice and their sponsors held to account.

Hours before the CCS meeting, Defence Minister Singh said people responsible for the "cowardly terrorist attack" on innocent citizens will soon get a befitting reply to their nefarious acts on Indian soil.

Singh also said India will not only hunt down those who perpetrated the attack but it will also trace the people who conspired to carry out the nefarious act on the Indian soil while "sitting behind the scenes".

The CCS that lasted for two-and-half hours decided to close the Integrated Check Post at Attari with immediate effect. It is the only operational land border crossing between the two countries.

The CCS decided that the Indus Waters Treaty of 1960 will be held in abeyance with immediate effect until Pakistan credibly and irrevocably abjures its support for cross-border terrorism, he said.

The Indus Waters Treaty, brokered by the World Bank to share the waters of cross-border rivers, is considered to be the most durable pact between the two sides.

On closing of the Integrated Check Post at Attari, Misri said those who have crossed over with valid endorsements may return through that route before May 1.

The CCS was briefed in detail on the terrorist attack on Tuesday in Pahalgam that left 25 Indians and one Nepali citizen dead, he said.

"A number of others sustained injuries. The CCS condemned the attack in the strongest terms and expressed its deepest condolences to the families of the victims and hoped for the early recovery of the injured," Misri said.

"Strong expressions of support and solidarity have been received from many governments around the world, which have unequivocally condemned this terror attack," he said.

The foreign secretary said the CCS recorded its appreciation for such sentiments, which reflect zero tolerance for terrorism. In the briefing to the CCS, the cross-border linkages of the terrorist attack were brought out, he said.

"It was noted that this attack came in the wake of the successful holding of elections in the Union Territory (Jammu and Kashmir and its steady progress towards economic growth and development," he said.

Misri said the CCS reviewed the overall security situation and directed all forces to maintain high vigil.

"It resolved that the perpetrators of the attack will be brought to justice and their sponsors held to account," he said.

"As with the recent extradition of Tahawwur Rana, India will be unrelenting in the pursuit of those who have committed acts of terror, or conspired to make them possible," he said.

In his address at the event, Defence Minister Singh said, "I assure the countrymen that in view of the incident, the government of India will take every step that is necessary and appropriate." "And we will not only trace those who perpetrated this incident. We will also reach out to those who, sitting behind the scenes, have conspired to carry out the nefarious act on the soil of India," Singh said.

The defence minister said, "India is such an old civilization and such a big country that it cannot be intimidated by any such terrorist activities." "The people responsible for such acts will get a strong response in the near future," he asserted. PTI MPB NSD NSD