A high-ranking Ugandan army officer who held senior post in President Idi Amin's government until he fled to Kenya earlier this month says that "Amin personally gave the order that all Lango and Acholi soldiers should be killed."

The officer, who refused to be identified, is one of the most important Ugandans to have left the country in recent weeks. He said that the orders were circulated throughout the country to army commanders via military radio a few days after the death of Anglican Archbishop Janani Luwum and two Cabinet ministers last month. He said he also was given the orders directly by one of President Amin's secretaries.

The officer escaped from Uganda earlier this month after he had been forewarned that his name was on a death list. "They were hunting Christians not because we made mistakes but just for the sake of killing Christians," he said.

The officer, who has served with President Amin in the army since 1960 before independence, said that when Amin, a moslem, took over in 1971 less than 5 per cent of the army was moslem. The figure is now probably over 20 per cent, he said.

"That 20 per cent is terrorizing the other 80 per cent whose morale is very low," the officer said. About 15 per cent of Uganda's people are Moslem, while 50 per cent are Christian and the rest aminist.

He blamed the current wave of Christian killings on jealousy. "Christians are better educated than moslems and by virtue of their education and ability they have been holding positions of responsibility," he said.

Most of the moslems, he said, are found in the dread State Research Bureau, which is the army's intelligence unit and is reportedly responsible for most of the killings in Uganda. There are very few Ugandan Christians in State Research, which is made up predominantly of members of Amins own Kakwa and related West Nile tribes and mercenaries from the Sudan, Zaire, Rwanda and Burundi.

The main function of State Research is "to insure the security of the president, not the country. Its members have full powers to kill people who are suspected of being uninterested in the government," he officer said.

Other moslems are now commanding officers. Some of these, including the vice president, Gen. Mustafa Adrisi, are reportedly illtiterate, although Uganda once had the highest standard of education in East Africa. Amin himself is believed to have left school after the fourth grade.

The officer believes he was on State Research's death list because he was a Christian in a high position.

The main targets are the Lango and Acholi in the army. The officer was unable to give precise figures and said he saw only 40 bodies himself but from reports he is convinced that "very many" perhaps 1,000 Lango, Acholi and other Christian soldiers have been killed since Anglican Archbishop Luwum died six weeks ago.

"It is not a new thing to see dead bodies along the roadside in Uganda," he said. When Amin seized power from Milton Obote in 1971, Lango and Acholi comprised about half of the country's 10,000-man army. Most of themwere suspected of being loyal to Obote, a Lango, and many of them were killed in 1971 and 1972.

When the recent wave of killings began last month just after the death of Archbishop Luwum, only the 3d Infantry Battalion had significant numbers of Lango and Acholi. The officer said "they were merely shot or butchered like cows."