JAIPUR: According to NDTV, six Border Security Force (BSF) personnel were wounded during an early morning mortar firing practice on Tuesday at the Kishangarh field firing range, over 100 km from Rajasthan capital Jaipur. Two personnel are critical, a senior BSF officer said.

The troops were participating in a firing exercise at the Kishangarh firing range started in 2012 when a 51 mm mortar shell blew up short of its target. The incident took place at about 8.30 a.m. The critically injured are being airlifted to Jodhpur; the other four have been admitted to a local medical facility, a BSF official said in Delhi.

The army too lost a soldier last week after a mortar shell exploded short of its target at a firing range near Arunachal Pradesh's Tawang. Six soldiers were also injured in this incident.

Tuesday's incident is the third reported accident this year involving mortars at a firing range of the BSF that guards India's border with Pakistan and Bangladesh.

A bigger and more powerful, 81 mm mortar, was accidentally blown up in January this year when BSF personnel were practising at the firing range. Two soldiers had lost their lives in this accident and three more, including an officer, were injured.

Another accident took place in March when a 51 mm mortar blew up, injuring four personnel. A few days later, six men of the border guarding force were injured in similar circumstances during mortar firing exercise in Jharkhand's Hazaribagh.

Manufactured by the government-run Ordinance Factory Board, a 51 mm mortar has a maximum range of about 800 metres and is built to function in sub-zero as well as high temperatures.