Fourteen rebels have been executed following disorders near Idiofa, about 300 miles east of Kinshasa, the official Zaire press agency reported yesterday.

Zaire's president, Mobutu Sese Seko, said that 67 army, officers and 24 civilians will go on trial today on charges of starting a campaign of urban terrorism. They allegedly were plotting to blow up a major dam, the Matadi-Kinshasa oil pipeline, stores, theaters, newspaper offices and the embassies of France and Morocco - two countries that helped the Mobutu government put down a rebellion in the southern Shaba province last year.

The press report did not say when the 91 were arrested or when the executions took place. Mobutu was quoted as saying the sabotage campaign was to have started the night of Feb. 18, ad the arrests may have taken place before then. Previous reports by Zaire dissidents in Belgium said there had been an attempted coup that week.

The plotters also allegedly planned to kill Mobutu's children, which Mobutu said was designed to shake him and provoke him to resign. The president's wife died in a Swiss hospital last October.

In Brussels, a Zaire opposition group called on U.N. Secretary General Kurt Waldheim to intervene to insure the rights of the 91 accused persons. The group also charged last month that troops had massacred 2,000 people in putting down the January uprising in the Idiofa area. The Zaire press report made no mention of a massacre and the Zaire Embassy in Belgium dismissed the committee's reports as "lies."