The Macedonian army has begun shelling mountain areas where ethnic Albanian guerrillas are believed to be hiding, witnesses said.
The bombardment started half an hour after a government deadline for civilians to evacuate the area passed at 3.30 p.m. (Irish time).
There had been a slight lull from midday after a morning of intense bombardments.
Witnesses near the village of Vakcince, the main target of bombardment by security forces, said shells were hitting a hill directly behind the hamlet.
Heavy smoke billowed from the woods, just metres behind the last house, they said.
The government has accused the rebels of keeping 3,500 ethnic Albanian villagers in the area against their will as a human shield to restrict their bombardment of the rebel positions.
Two villagers have so far been killed in the fighting, the International Red Cross said.
