India on Wednesday test-fired the 3,500-km range surface-to-surface nuclear capable Agni-III missile from the Wheelers' Island off Orissa coast.

The intermediate range ballistic missile (IRBM) was test-fired from a mobile launcher from the launch complex (LC-4) of the integrated test range (ITR) around 9:56 am, defence sources said.

The 16 metre-long and 1.8-metre wide missile roared into the sky in a vertically slanted position leaving behind a thick column of orange and white smoke and, within seconds, became invisible to the naked eye, an eyewitness said.

Agni-III missile is fitted with on-board computer for its guidance system.

A battery of sophisticated radars, electro -optic tracking systems, telemetric data centres in the mainland apart from two naval war ships anchored near the impact point, were engaged to monitor the entire trajectory in today's test launch.

"The test result will be known after detailed analyses of the flight data recovered," the sources said.

Weighing about 48 tonnes, the Agni-III missile was first test-fired on July 9, 2006 but it failed to meet its mission objectives due to cascaded failure of booster flex nozzle controller.

However, during the second test conducted on April 12, 2007, the entire flight path of 15 minutes duration validated all mission objectives, they said.