By Peter Apps

COLOMBO, Aug 21 (Reuters) Sri Lankan officials and aid workers loaded a ship today to take supplies to the besieged north after weeks of fighting between the army and Tamil Tiger rebels that seems to have achieved little more than a stalemate.

Both sides have been on the offensive for the first time since a 2002 ceasefire, first devastating the northeast area near the port of Trincomalee and then fighting on the northern Jaffna peninsula leaving it cut off for more than a week.

Exact body counts are non-existent, but diplomats and analysts say it is clear hundreds are dead. More than 160,000 people have fled their homes, and basic commodities are running out in Jaffna after road, sea and air links were cut.

The Red Cross said a small convoy of vehicles was headed out of rebel territory in the north, where they had been trapped by the fighting.

''They are mainly aid workers, but there are also other foreign citizens who have been in the Vanni and been surprised by current events,'' said Peter Krakolinig, deputy head of the International Committee of the Red Cross (ICRC) in Sri Lanka. A ship flying the Red Cross flag was due to sail from the capital for Jaffna as soon as possible, he said, but rain is delaying the loading of food.

Another ferry will also likely sail to collect civilians and the wounded. Many Jaffna residents have registered with government and Red Cross officials to get out. But for now, the only plan is to evacuate the few hundred with foreign passports as well as some of the aid staff trapped by the fighting.

NO BREAKTHROUGH The United Nations, United States, European Union and others have all called for a cessation of hostilities. But the Liberation Tigers of Tamil Eelam (LTTE), who have fought for two decades for an ethnic Tamil homeland, say talks are impossible.

Three weeks after the infantry battle erupted as troops moved forward to try and take control of a rebel-held water sluice gate south of Trincomalee, the front lines are almost exactly where they were in 2002.

''Today is quiet,'' said an army spokesman. ''In Jaffna, The troops are consolidating the defence line. Sometimes they come and fire artillery at us and we retaliate. The same as yesterday.'' The army say they now hold the sluice, although diplomats are unconvinced. The Tigers appear to have pushed the front line on the Jaffna peninsula maybe a mile north.

After weeks of fighting, the army says the area south of Trincomalee is now quiet. Aid staff say that what that really means is little infantry fighting but near continuous artillery fire. Most of the civilian population has now simply fled.

But Jaffna, a Tamil town controlled by soldiers from the majority Sinhalese army, is still seen as a key rebel goal and with supply lanes cut off, few are willing to rule out an eventual Tiger attempt to break through and seize it.

A pro-rebel Web site showed photographs of rebel fighters walking to the front through dense jungle, laden down with ammunition, entrenching tools, and rocket propelled grenades.

REUTERS LL BS1332