Indiainfo-icon's top counter-terrorism agency on Monday charged Jaish-e-Mohammad (JeM), and its top leader, with perpetrating a deadly attack on an Indian air force base in January.

The National Investigation Agency (NIA) stated that all four gunmen who stormed the air base on Jan 2 were Pakistani nationals and that Maulana Masood Azhar, the top leader of JeM, was the mastermind behind the attack.

 "All the terrorists are accused of waging warinfo-icon against India. This was a criminal conspiracy to attack our security infrastructure," said a senior official at the NIA in New Delhiinfo-icon.

The presentation of a charge-sheet to a trial courtinfo-icon wraps up India's investigation into the 18-hour siege at the Pathankot air base in which seven Indian security personnel and the four assailants were killed.

The attack, which came a week after Indian Prime Minister Narendra Modi paid an impromptu visit to his Pakistani counterpart, Nawaz Sharifinfo-icon, derailed a tentative thaw between the nuclear-armed rivals.

A joint investigation into the attack went nowhere and tension between the neighbors has risen over the course of a year marked by protests and cross-border clashes in the disputed region of Kashmirinfo-icon.

Investigators in New Delhi said the charge-sheet and evidence would be offered to Pakistani authorities to take action against the perpetrators of the attack. "We want Pakistaninfo-icon to arrest Maulana

Masood Azhar and he should be deported to India," said a senior Indian home ministry official who is overseeing the investigation.

The charge-sheet cited DNA samples, foodinfo-icon packets from Pakistan found in woodlands near the air base, a walkie-talkie set and a note found in a car used by the militants to drive to the base.

India has long accused Pakistan of using Jaish-e-Mohammad as a proxy to mount attacks on Indian soil and had earlier given what it called "actionable intelligence" to Pakistan, including telephone intercepts.