The leader of a military uprising was placed under arrest Monday and his followers surrendered one of two bases they held for five days. Rebels said they would give up the other base Tuesday, news reports said.

Questions persisted about whether a secret deal was made with the rebels, who demanded an end to prosecution of officers charged with human rights abuses during eight years of military dictatorship that ended in 1983.Defense Minister Horacio Juanarena was to brief the Senate on Wednesday on how the government ended the uprising, which Argentines considered a threat to their 5-year-old democracy.

President Raul Alfonsin has said no concessions were made to the rebels.

Rebel spokesmen denied they surrendered and said they negotiated a cease-fire that allows them to return, unpunished, to their units.

The leader of the estimated 500 rebels, Army Col. Mohamed Ali Seineldin, surrendered Monday night and left the infantry school on the Campo de Mayo base just outside Buenos Aires, where he and some followers had been holed up.

Seineldin organized the dismantling of the defenses, including trenches and land mines, he and his comrades had set up at the arsenal.

Shortly afterward, several army trucks left the arsenal carrying cheering troops, according to the private news agency Diarios y Noticias. It was not immediately known where the trucks were headed.

Army chief Lt. Gen. Jose Dante Caridi said Seineldin would be held at a military prison. No mention was made of a trial or punishment for him or his supporters.

More rebels were at a base at Mercedes, about 60 miles west of the capital. The government news agency Telam said rebels intended to turn over that base to the government Tuesday.