NEW DELHI --
Indian airports were on high alert Friday after intelligence services received information that al-Qaida-linked militants were plotting to hijack a plane.
Such an attack would be the first major terrorist strike in India since 10 heavily armed militants rampaged through the commercial capital Mumbai for three days in November 2008, killing 166 people.
Airports were placed on alert Thursday after the government received warnings from intelligence agencies, aviation spokeswoman Moushumi Chakravarty said.
A report in The Indian Express newspaper, which Chakravarty confirmed, said intelligence officials had uncovered a plot by militants linked to al-Qaida and the Pakistan-based Lashkar-e-Taiba group to hijack an Air India or Indian Airlines flight destined for a neighboring South Asian country.
U.K. Bansal, a top home ministry official, said security was tightened at all airports and passengers were being subjected to more intense security screenings.
Sky marshals will also be deployed on some flights, the home ministry said in a statement.
Indian media said the hijack threat was uncovered during the interrogation of Amjad Khwaja, a militant leader belonging to Harkat-ul-Jihad-al-Islami, an extremist group involved in numerous terrorist attacks in India.
Khwaja was arrested in the southern Indian city of Chennai last week and was being questioned by Indian police.
Harkat-ul-Jihad-al-Islami is said to have similar motivation and goals as both al-Qaida and Lashkar, but it is unclear whether they have direct links.
The terror alert came just days after U.S. Defense Secretary Robert Gates warned that a syndicate of terrorist groups affiliated with al-Qaida was trying to foment a new war between India and Pakistan.
The nuclear-armed neighbors have fought three wars, and efforts to resolve their long-running dispute over the Kashmir region were frozen after the Pakistan-based militants attacked Mumbai in 2008.
Gates praised India for its restraint after the Mumbai attack, but expressed concern that the government would have a hard time reacting so cautiously if it were hit again.
In December 1999, Islamic militants hijacked an Air India flight from Nepal's capital, Katmandu, to Kandahar in southern Afghanistan.
The hijacking ended when New Delhi released four Islamic militants in exchange for 167 passengers and crew.