While one missile was test-fired from the Integrated Test Range at Chandipore-on-sea in the eastern Orissa state, the second missile was launched a minute later from Wheeler’s Island in the Bay of Bengal, the PTI news agency reported.

The trajectory of both missiles was programmed to intercept each other in mid-air over the Bay of Bengal, officials said.

“The missiles successfully collided against each other. We are analysing the data,” ITR director AK Checker told IANS news agency.

Checker said the tests were conducted under the “Prithvi Air Defence Exercise” (PADE), which was conducted for the first time to validate the missile’s operational effectiveness.

“While the missile from ITR was the attacker, the one from Wheeler Island was to act as the defender,” a defence ministry source told the agency.

Defence experts told local TV channels that Monday’s test was significant as the Prithvi missiles would be deployed to provide air defence cover for India’s nuclear installations as well as metropolitan cities including New Delhi, Mumbai, Kolkata and Chennai.

Prithvi, which means “earth” in the Hindi language, has a range of 150 to 250 kilometres and is capable of carrying a payload of between 500 kilos and one ton, including nuclear weapons.

The missile takes 300 seconds to reach the target located at a distance of 150 kilometres.

Two versions of the missile have already been deployed with India’s army and air force. A third version with a longer range of 350 kilometres is currently under development.

Prithvi is India’s first indigenously built ballistic missile. It is one of the five missiles which are being developed under India’s integrated missile development programme that includes the intermediate-range ballistic missile Agni, the surface-to-air missile Akash and the anti-tank missile Nag.

The air defence exercise will be followed by a three-day conference on range technology at ITR from Tuesday, which will be attended by 15 renowned defence scientists from US, Germany, Britain, France and Denmark.