India has put several international airports on "red alert" following repeated e-mailed threats to target air facilities in New Delhi, Bangalore and Chennai and hijack airliners.  From New Delhi, VOA Correspondent Steve Herman reports the increased security comes in wake of last week's terror attack in Mumbai, which killed about 175 people, and the anniversary of the destruction of an Indian mosque.

An Indian paramilitary soldier checks the luggage of air passengers during heightened security checks at a domestic airport in New Delhi, India, 04 Dec 2008

Although some security experts are casting doubt on the authenticity of e-mailed messages warning of more terror attacks in India, authorities are taking no chances.  They have put all civil airports on alert and are making closer and repeated inspections of passengers' luggage.

Threatening e-mails sent to media organizations (including the Voice of America) have been traced to a computer relay server in Saudi Arabia.  But analysts say they do not match the pattern and language of previous credible communications received from the obscure group known as "Deccan Mujahideen."  E-mails in that name were sent immediately surrounding several bombings, earlier this year, in Indian cities.

Indian officials contend last week's attack on Mumbai was carried out by gunmen who came from Pakistan and who are linked to the terrorist organization Laskhar-e-Taiba.

Contributing to the apprehension is the anniversary of the destruction of the Babri Masjid in Uttar Pradesh.  The mosque - constructed by the first Mughal emperor - was demolished by Hindu activists on December Sixth, 1992. The act inflamed Muslim sentiment.

The latest e-mail threats specifically mention the international airports at Bangalore, Chennai and New Delhi.

Indian newspapers and television stations quote sources as saying that, in addition to the e-mails, specific intelligence has been received that terrorists are planning an assault at airports or hijackings.

India's air chief marshal, Fali Homi Major acknowledges warnings of a 9/11 type aerial attack have been discussed by military service heads.

"This is based on little warning which has been received, that's all. Nothing else," he said.  "We are prepared, as usual."

When asked whether airport security would ber stregthened further, Major stated that he "can't reveal that."

India media say sky marshals have been put on some flights and dogs able to sniff explosives are being deployed at airports.  Passengers are going through an additional layer of body frisking and hand-baggge inspections before they board aircraft.

As a result of the Civil Aviation Bureau's "anti-hijacking alert," domestic passengers are being asked to arrive at affected airports two hours, in advance, and those taking international flights should check in four hours before departure.

India's military and intelligence agencies have been stung by allegations that they had information - including relayed telecommunications intercepts from the U.S. government - which, if acted upon, could have prevented the Mumbai attacks.