Nationalist insurgents abducted 400 African pupils from a Protestant mission over the weekend and took them to neighboring Botswana for guerrilla training, the Rhodesian military announced tonight.

The statement also said that the raiders stole $20,000 in school fees and kidnaped five teachers, two nurses and a clerk.

The Rhodesian Foreign Ministry issued a sharp protest tonight at what it said was Botswana's complicity in the incident.

The alleged kidnaping took place yesterday at the Manama Lutheran Mission's secondary school in the south, 15 miles from the Botswana border. The mission runs a school for students between the ages of 12 and 20.The statement said that 230 male students and 170 females were kidnaped.

The mass abduction immediately recalled a similar incident in mid-1973 when guerrillas took 350 students from St. Albert's Roman Catholic mission in northeastern Rhodesia. Pursuit by security forces brought the return of all but 25 of the mission pupils in that case.

In the Manama Mission incident, the proximity of the Botswana border has ruled out any military operation to return the children.

The school's headmaster, Jeffias Diza, 39, said that the incident began when an armed insurgent burst into his office demanding school fees for the current term that had been collected that morning.

"After I had got the money together from my house where my wife had hidden it, I stepped outside and saw the whole school streaming through the gates," Diza said. "There was no violence, but the terrorists were shouting and saying that everybody had to come and join the ZAPU army. One of them said he would kill those who didn't come but I couldn't really tell whether the children were going of their free will or not."

Five of the students later managed to escape and return to the mission. Two of the teachers also left the group, which was led off toward the Shashe River separating Rhodesia and Botswana.

The incident is the latest in a series of recruitment raids mounted in southwestern Rhodesia by ZAPU (Zimbabwe African People's Union) guerrillas loyal to nationalist leader Joshua Nkomo.

This recruiting campaign began in October during the geneva conference. The government claims that all recruitment in the area has been conducted at gunpoint. The guerrillas say that they are merely tapping a huge and willing reservoir of young would-be insurgents.

In the past, guerrillas have regularly led recruits across the border on foot to village pick-up points in Botswana. The recruits are trucked to Francistown and flown to Zambia where they are taken to ZAPU camps for training.

It is officially estimated that around 1,000 African youngsters have left or been taken from southwest Rhodesia for training in ZAPU camps since October.

In the previous 15 months, only 600 left the same area for Botswana.

The recruitment is essential to Nkomo's professed plans to build up his own fighting forces, which have always been much smaller than the guerrilla army of Robert Mugabe operating from Mozambique.

Botswana has frequently denied that it allows guerrillas use of the country as a base for attacks on Rhodesia. But there has been little attempt to conceal the fact that guerrilla recruits. Rhodesian army deserters and those generally on the run from Rhodesian authorities use Botswana as a convenient escape route.

Although the level of guerrilla activity in the southwest has been low compared to the east, there has been a steady increase over the last three months of incidents involving ZAPU insurgents.

ZAPU has traditionally used Zambia as a jumping-off point for these attacks, but there is circumstantial evidence that Botswana is now prepared to allow guerrillas the freedom to operate from its territory.

In Lusaka, Zambia, British envoy Ivor Richard ended his month-long shuttle tour of southern Africa today, with no firm indication of how efforts to achieve a peaceful settlement in Rhodesia could be revived, Reuter reported.

[Sources in Richard's delegation said that greater participation by the United States in peace moves and South African pressure on Rhodesian Prime Minister Ian Smith could be part of a new initiative, but they said. Richard had no definite plans for resuming his mission, aimed at restarting the stalled Geneva conference on implementing a black majority in Rhodesia.]