Rwandan troops fought with guns and bombs for an eighth day to neutralize rebel invaders in the north of their tiny east African country, diplomats said, while shooting resumed in the paralyzed capital city of Kigali.

Western diplomats in Kigali, asking to remain anonymous, said they understood the Rwandan army was still meeting stiff opposition Sunday from the 2,000-strong army of a former refugee and guerrilla warfare expert. The forces under Maj. Gen. Fred Rwigyema stormed into the country Sept. 30 from neighboring Uganda, apparently without that country's knowledge or sanction.In Paris, World Bank representative Jean-Claude Fayd Herbe, who flew in overnight with 252 other western fugitives from the fighting, told reporters he understood the Rwandans were bombing the Ugandan frontier to flush the rebels from the thick bush that covers much of the hilly landscape.

German evacuees in Nairobi said rebels were under repeated helicopter attack, causing speculation about whether Rwanda's forces were receiving active outside military assistance, possibly from the 500-odd Zairean troops sent at the request of President Juvenal Habyarimana.

Rwanda's military has only two helicopters.

Rwigyema's stated aim is the overthrow of Habyarimana's Hutu-dominated government, but his forces include exiled Hutu enraged at the president's assertion this year that there is no room for returning refugees in overpopulated Rwanda. Rwanda has the highest population density in Africa - 998 people per square mile.