Army leaders assumed direct rule in this former Dutch colony today after forcing the president to resign and arresting one of the leaders of last February's military coup.

The Army leaders accused "ultra-left" and conservative soldiers and politicians of involvement in efforts to undermine the government of the South American nation of 350,000.

It was announced that Prime Minister Henk Chin A Sen had taken over the post of president, succeeding Johan Ferrier, 70, who resigned late Wednesday.

[Although it was reported that Ferrier was forced by the ruling National Military Council to resign, Radio Nederland reported that he resigned after the military leaders rejected an ultimatum to present a budget by Sept. 1 and reinstate the now-dissolved parliament to discuss the budget.]

[The Dutch radio report, monitored in Washington, said Ferrier threatened to resign by Nov. 1 if his ultimatum were rejected.]

Both the Netherlands, which still gives Surinam extensive financial support, and the United States have strongly backed Ferrier in his attempts to moderate the youthful military leaders, who virtually had the country handed to them after a noncommissioned officers' revolt over the elected government's refusal to let them form a union.

Ferrier held the largely ceremonial post since Surinam became independent Nov. 25, 1975.

According to various reports, the National Military Council closed the country's borders, imposed a 7 p.m. to 4 a.m. curfew and said it would censor all news reports. The reports said several persons, including former council member Badressin Sital and six former Cabinet ministers, were being held. A report that former prime minister Henck Arron had been rearrested after being released from house arrest only days ago could not be confirmed.

In announcing a state emergency, Army chief Desi Bouterse said the bureaucracy was stalling efforts to "clean up the country in every respect," and inflation and demands for pay raises were causing growing unrest.

President-designate Chin A Sen said the government would not tolerate agitation from extremes of either the left left or right.

Surinam, a nation the size of Georgia on South America's northeast coast, is the world's fourth-largest exporter of bauxite and provides the United States with about one-fourth its imports of the aluminum ore.