JAKARTA -- Seven members of the Indonesian armed forces (TNI) were killed in a fierce assault by separatist rebels in the restive Aceh Province, the military said Tuesday.

Lieutenant Colonel Ahmad Yani Basuki, spokesman of the military operation in Aceh, said seven others soldiers were injured in a battle that started Monday and ended Tuesday morning in Matang Kumbang village of Bireuen district.

It was the worst casualty toll for the TNI since the launch of a massive military operation against the separatist Free Aceh Movement (GAM), started three weeks ago in Indonesia's northern Aceh Province.

Basuki said the clash began on late Monday afternoon and lasted until at about 8 a.m. on Tuesday, DPA reported.

The military spokesman said three bodies were recovered from the scene, while four others were still in the field, adding the wounded soldiers were rushed to the military hospital in Lhokseumawe, 1,660 kilometera northwest of Jakarta.

Basuki said the GAM also suffered a large number of casualties, but he could provide immediate details.

Indonesia imposed martial law in Aceh on May 19, ordering the military to launch an all-out offensive against GAM rebels, who have been fighting for an independent state in Aceh since 1976.

Local media reports from Aceh claim as many as 162 GAM rebels were killed during the first three weeks of military operation in Aceh, while 100 others were arrested and another 102 have surrendered.

***Media Indonesia***, an Indonesian daily, said on Tuesday at least 18 civilians were killed, while 16 Indonesian military and police officers have lost their lives, excluding the seven killed Tuesday.

Another 33 government officers have been wounded.