At least 18 people have been killed, including 12 soldiers, after Shining Path fighters ambushed a Peruvian military convoy in the country's south, military sources say.

A child was among six civilians killed in the ambush on Thursday night on a convoy transporting troops and civilians in Huancavelica province, about 250km southeast of the capital Lima, military officials said.

The clash occurred near the coca-growing Apurimac and Ene valleys. Peru is the second-largest producer of coca, is also used as a raw ingredient for cocaine, after Colombia.

The Shining Path, which has led an insurrection against the government for decades, had been considered a spent force.

Its campaign between 1980 and 2000 left 70,000 people dead, a National Truth and Reconciliation Commission found in 2003.

'Dirty war'

Peruvian authorities say the group has largely abandoned its Maoist ideology in favour of drug-running, that its leaders had originally started to fund its operations.

Abimael Guzman, the group's founder, and much of its senior leadership, were captured and imprisoned throughout the 1990s.

The military said it killed five suspected Shining Path fighters earlier in the week after one soldier was killed while on patrol.

The military has been conducting an offensive in the Vizcatan jungle region of Peru, where 300 Shining Path fighters are believed to be.

Alberto Fujimori, the Peruvian president from 1990 to 2000, is currently on trial for human rights violations and has been accused of conducting a "dirty war" against members of the Shining Path and the Tupac Amaru armed group.