The Nepali security forces have discovered at least 50 bodies of anti-government guerrillas who were killed early Friday morning when the security personnel repulsed a major overnight attack by the guerrillas in mid-western Nepal.

"As many as 4,500 rebels Thursday evening attacked the security base at Khara in Rukum district, some 500 km west of Kathmandu, and the two-way gun battle continued till early Friday," a local army officer said.

Nine security personnel were injured in the battle, three of them seriously.

Ground and air surveillance is already underway in the region, and the number of casualties on the part of the insurgents could be much higher, the officer said on condition of anonymity.

This is the first major offensive attempt made by the insurgents since a state of emergency was imposed in Nepal on Feb. 1.

More than 11,000 Nepalese people have lost their lives since the anti-government insurgency broke out in February 1996.