Government increases security at airports and orders use of sky marshals amid warnings of Islamist terrorist plot to hijack plane

Airports in India were put on high alert today after intelligence reports of a terrorist plot to hijack a plane.

The Indian government also directed airlines to deploy sky marshals on a number of routes between countries in south Asia.

Terrorist groups with links to al-Qaida or Lashkar-e-Taiba, the Pakistan-based group behind the Mumbai attack in 2008, were planning to seize a plane operating in the region, according to intelligence reports cited by the Press Trust of India.

The warning comes in the run up to next Tuesday's annual republic day in India, when there are often security scares.

Routes to India from countries in the South Asian Association for Regional Cooperation are thought to be especially vulnerable. They are Nepal, Bangladesh, Sri Lanka, Bhutan, Maldives, Afghanistan and Pakistan.

Sky marshals have been ordered on board planes flying on routes between India and these countries. India has also advised these seven countries to step up security at their airports.

Despite volatility in the region, India has been spared a major terrorist attack since the Mumbai incident, when 10 militants attacked the city for three days in November 2008, killing 166 people.

Aviation spokeswoman Moushumi Chakravarty said that the airports were placed on alert yesterday after the government received the warnings.

A report in The Indian Express newspaper, which Chakravarty confirmed, said intelligence officials had uncovered a plot by militants to hijack an Air India or Indian Airlines flight destined for a South Asian country.

UK Bansal, from India's home ministry, told Reuters: "We have alerted our civil aviation security people against a possible attempt to hijack an Indian airlines flight."

He added: "This would obviously be from terrorist groups who are arraigned against Indian interests." He did not specify which group.

The 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 terror attacks in India.

Khwaja was arrested in the southern Indian city of Chennai last week and was being questioned by Indian police.

The terror alert came just days after the US defence secretary, Robert Gates, warned that a syndicate of terror groups affiliated with al-Qaida was trying to foment a new war between India and Pakistan.

Gates praised India for its restraint after the Mumbai attacks, 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, Kathmandu, to Kandahar in southern Afghanistan. The hijacking ended when New Delhi released four Islamic militants in exchange for 167 passengers and crew.