The trial of Arjun Mark II tanks has started at Rajasthan's Pokhran field firing range, the Defence Reasearch and Development Organisation has said.

"The trials started on Friday last and will continue for the next two months. The ongoing trials will mainly focus on 19 parametres," DRDO spokesperson Ravi Gupta said in a press statement issued in Jaipur on Sunday.

"Indian Army accepted 124 Arjuns into service but the Army has made a follow-on order conditional upon 93 improvements to the Arjun, including 19 major modifications," defence spokesperson S D Goswami said.

The major upgrades would be missile-firing capability against long-range targets, panoramic sight with night vision to engage targets effectively at night, containerisation of the ammunition, enhanced main weapon penetration; additional ammunition types, explosive reactive armour, an advanced air-defence gun to engage helicopters.

Other upgrades are an enhanced auxiliary power unit providing 8.5 KW (from 4.5 KW) and an improved gun barrel, changes in the commander's panoramic sight with eye safe LRF, night vision capability including for driver, digital control harness,' he said.

This tank is the successor to Arjun Mark 1 Tank.

An Arjun tank is operated by a four-member crew comprising a commander-cum-navigator, gunner, loader and driver.