'Heavy army losses' in Sudan

Speaking from the Eritrean capital, Asmara, SPLA spokesman Yasser Arman said that government planes had been bombarding the opposition in Old Rassai.

There is no independent confirmation of the claims.

The rebels accused government force of launching an attack just 10 minutes after agreeing a truce across Sudan

The agreement to suspend hostilities was signed two days ago and came into force on Thursday at 0900 GMT, as peace talks resumed in the Kenyan town of Machakos

The two sides have begun discussing a political settlement to end 19 years of conflict between the Arab and Muslim dominated north and the mainly Christian and animist south.

An estimated two million people have died in the conflict, and negotiators believe a ceasefire must be in place if progress is to be made with the overall peace process.

First truce

The first truce ever agreed between the two sides, which lasts as long as the peace talks continue, covers all parts of Sudan, despite government attempts to exclude eastern areas, where rebel forces have recently made gains.

In July, the two sides made a breakthrough on the political front, when the government agreed to hold a referendum on secession for the south, and also accepted not to impose Islamic Sharia law on the south.

The peace process was then held up as both sides launched major offensives.

The SPLA took the key southern garrison town of Torit in early September, prompting the government to withdraw its negotiators from Machakos.

The army retook Torit last week.