Tamil Tiger rebels in Sri Lanka say eight top aides of a breakaway rebel leader have been shot dead in a suburb of the capital, Colombo. The dead are said to include Colonel Karuna's bodyguard and finance chief. The killings come as a Norwegian peace envoy arrives for fresh talks, after warning that the current situation could plunge the country back into war. A recent surge of violence seems to be turning into a low-level guerrilla war between the Tigers and Colonel Karuna. The Tigers have long argued that Colonel Karuna is working with the army and in this instance, they allege a military intelligence officer was among the dead. The government and the army have strenuously denied any involvement with the rebel defector. **Upsurge in violence*** The Sri Lankan army and police have yet to confirm the incident, though one captain said he was getting calls from senior officers about something big that had happened. There is little doubt the Tigers are first with the information because they carried out the killings. It is part of an upsurge of violence in recent weeks that seems to be developing into a low-level intensity guerrilla war between the Tigers and Colonel Karuna - allegedly, with army support. Norway's deputy foreign minister, Vidar Helgesen, who starts a fresh round of talks in Sri Lanka on Sunday, has already warned that the current situation is very dangerous. **PHOTO CAPTION*** The Tigers argue that Colonel Karuna is working with the army. (AP)