Five days after the fall of their dictator, Haitians have begun open political activity with public disputes, personal ambitions and at least two candidates for president.

The swift emergence of vocal government critics and political contenders demonstrated the pressure for change released by the departure of Jean-Claude Duvalier and a promise of democratic government here after two generations of family dictatorship. It also underlined the challenge faced by Haiti's new ruler, Lt. Gen. Henri Namphy, in keeping public order while carrying out his pledge to restore democratic freedoms and organize elections for a new government.

Namphy's military-dominated National Council of Government has turned its attention first toward restoring order after several weeks of protest demonstrations against Duvalier followed by vengeance attacks against his political police, the Ton-Tons Macoutes. Although the situation remains volatile, according to military officers, the beginning of a nighttime curfew has been pushed back from 6 p.m. until 10 p.m., and mob attacks on Ton-Tons Macoutes, officially known as the Volunteers for National Security, largely have stopped.

Col. Williams Regala, the new minister of interior and national defense, has ordered all unauthorized arms turned in by noon Thursday. The measure, announced today, appeared to be aimed chiefly at Ton-Tons Macoutes who have not yet been disarmed by Army troops and remain in hiding.

Namphy's pledge to organize elections and reinstate political freedoms drew a favorable response today from Hubert de Ronceray and Gregoire Eugene, vocal Duvalier opponents who already have declared that they intend to run for president. Both expressed support for Namphy's council and voiced confidence that the general will remain faithful to his promises.

De Ronceray said, however, that some of his youthful followers have complained strongly that the council and its 13-member Cabinet contain mostly figures known to have worked with Duvalier before his fall. For the time being, de Ronceray said, he is advising his followers to hold off on criticism even if the Cabinet appears unsatisfactory to them.

De Ronceray named four Cabinet members as particularly unsuitable because of their government records under Duvalier: Commerce and Industry Minister Odonel Fenestor, Social Affairs Minister Thony Auguste and Montaigu Cantave, minister of agriculture, natural resources and rural development.

He did not detail what made them more objectionable than others. But according to a witness, Agriculture Ministry workers prevented Cantave from entering his new office yesterday on the ground that he was too closely identified with the dictatorship.

"These people should not be in the government," de Ronceray said. "It bothers me. It bothers me a lot . . . . If, after a reasonable period, the council does not show the ability to give satisfactory answers to the demands of the people, I would be among the first leaders to call on the people to resist."

Another longtime Duvalier opponent and possible candidate, Silvio Claude of the small Christian Democratic Party, told reporters that the provisional Cabinet should include anti-Duvalier figures to show the Haitian people a new era has begun. His criticism was reported on the government's National Radio, which under Duvalier broadcast only progovernment news.

Of the five council members and 13 Cabinet members, only Justice Minister Gerard Gourgue of the Haitian Human Rights League had been a visible Duvalier opponent before his downfall. Namphy was chief of staff in Duvalier's armed forces and was designated by Duvalier personally to take command of the country when the president left Friday.

Eugene said, however, the new government's makeup has little importance because it is designed only as a transition body to prepare the way for electing a permanent government.

"The provisional government does not reflect the face of the new Haiti after Duvalier," he said. "I don't care who is in the government now. All I want is assurance that we are heading for free elections."

Setting a date for parliamentary and presidential elections appeared likely to become a key test of the council's ability to retain support from political activists such as Eugene, de Ronceray and Claude, all of whom suffered repression under Duvalier.