Colombo  - Several loud explosions were reported from the rebel-controlled area in northern Sri Lanka where at least 50,000 civilians are believed to be, the military reported Wednesday.

The explosions were heard from the 17-square-kilometre safe zone declared by he government for civilians in the Puthumathalan area, 395 kilometres north-east of the capital on Wednesday.

The military said the explosions occurred after the army made public announcements calling the rebels to surrender and allow civilians to leave.

The army used loudspeakers and Tamil-speaking soldiers to make the announcements.

Since January some 60,000 civilians have left the area on their own or have been evacuated by the International Committee of the Red Cross.

The army said it is in the final phase of a drive to end the 26-year ethnic conflict in Sri Lanka.

During the week the army claimed they killed more than 400 rebels.

But rebels have been claiming that civilians have been hit by the security forces in the safe zone.

There is no independent confirmation about the casualty figures provided by the military or those claimed by the rebels of the Liberation Tigers of Tamil Eelam.(dpa)