COLOMBO, Sri Lanka (AP) _ Seven more skeletons have been discovered in a sewage pit at a sports stadium in northern Sri Lanka, raising to 23 the number of human remains found in the last week, officials said Monday.

The excavation at the Durayappa Stadium in Jaffna, 190 miles north of the capital, Colombo, began last week after municipal workers noticed a few bones when cleaning the pit.

In the first three days, 16 skeletons were recovered, and seven more were found over the weekend, an official said on condition of anonymity.

Government officials declined to comment on the remains but said they were being sent to Colombo for investigation.

The startling discovery came amid preparations to exhume an alleged mass grave at Chenmani, six miles from the stadium, where a convicted soldier testified in court that he had helped bury more than 400 bodies of people killed in custody.

The Chenmani excavation will start June 16, nearly a year after the soldier leveled the charges against the military. He was convicted of raping and murdering a Tamil girl.

Relatives of missing people have claimed more than 600 people were taken away by the military after the city was captured from Tamil rebels in 1996. The battle for Jaffna was one of the bloodiest in Sri Lanka's 16-year ethnic war.

Maj. Gen. Lohan Gunawardhane said recently only 300 complaints have been lodged about missing persons, and most of them apparently fled Jaffna and could be living in rebel-held territory.

Tamil rebels who are fighting for an independent homeland claim they face severe discrimination at the hands of the Sinhalese majority. Tamils make up 18 percent of the country's 18 million people and the Sinhalese, 76 percent. About 58,000 people have been killed since 1983 in Sri Lanka, an island nation off the tip of India.