New Delhi, Dec. 26: India today test-fired its inter-continental ballistic missile, Agni 5, for its full range of 5,000-plus kilometres, defence scientists said, and claimed it was a success.

The 17-metre-long Agni 5 is being developed as India's strategic deterrent - to be used in pursuance of its "no first strike" policy that itself may be reviewed.

The Defence Research and Development Organisation (DRDO) said in a statement that the missile was fired from Dr Abdul Kalam Island - earlier known as Wheeler Island - on the Odisha coast. It was launched from a canister on a road mobile launcher. The three-stage solid-fuel powered rocket splashed somewhere in the southern Indian Ocean after a 20-minute flight.

The DRDO said all radars, tracking systems and range stations monitored the flight.

"The full range test-flight of the missile has further boosted the indigenous missile capabilities and deterrence level of the country," said the DRDO statement.

This was the fourth test of the Agni 5 - the second one from a canister on a road mobile launcher, probably a multi-wheeled flatbed truck.

Sources in the DRDO said the missile was capable of bringing most targets in China and beyond within its range when fired from launch base deep in the Indian hinterland.

DRDO sources said the missile was now "user-deliverable". This probably means that the Strategic Forces Command (SFC), which is the custodian of nuclear assets, can take possession of the missile. It would take more "user-trials" for the missile to be fully operational by the SFC.

The Agni 5 can carry a nuclear warhead of a tonne. The tests are done with a payload of the same weight. The first test was in April 2012.

"Successful test-firing of Agni V makes every Indian very proud. It will add tremendous strength to our strategic defence," Prime Minister Narendra Modi tweeted shortly after the test-firing and before an official announcement from the DRDO.

President Pranab Mukherjee and defence minister Manohar Parrikar also congratulated the scientists.

The Agni 5 is the longest-range missile being developed by the DRDO. The others in the Agni series have ranges of 700km (Agni 1), 2000km (Agni 2), 2500km-3500 km (Agni 3 and Agni 4).