Sudan's prime minister promised political change Sunday but charged that demonstrators who rioted against price increases were "struck by madness" and seeking illegal political gains.

At least four people died, apparently all in one Khartoum shooting incident, during four days of street violence last week that led to a general strike.After the strike began Thursday, the government backed down, rescinding steep price increases and making salary hikes for millions of Sudanese retroactive to July 1.

The demonstrators then changed their focus mainly into a protest of Prime Minister Sadek Mahdi's failure to endorse a draft peace accord signed Nov. 16. The protests finally ended Saturday.

Trade unions and political parties also remain unsatisfied with the government's stand. They scheduled a meeting with Mahdi on Monday to discuss further economic reforms and peace.

In a nationally broadcast speech marking Sudan's 33rd anniversary of independence from Britain and Egypt, Mahdi named no names in his bitter attack on demonstration organizers.

"Some people want to make use of legal differences, some who have been struck by madness," Mahdi said at a rally in el-Obeid, 200 miles southwest of Khartoum. "For them to try and develop these differences into an uprising is harmful and wrong.

Mahdi promised political changes but didn't specify whether he meant economic reforms or stepping up efforts to end the war.

"Our next steps in the government are holding wide consultations and serious, responsible studies to review our performance," he said in the speech broadcast over the official Omdurman Radio.

The Democratic Unionist Party, which negotiated the peace treaty with southern rebels, has quit the governing coalition. Party leaders said they wanted to express sympathy with the strikers and to dramatize their outrage at Mahdis' handling of the proposed agreement to end Sudan's 51/2-year-old civil war.

The Democratic Unionists dominate the 2-million-member Sudanese Workers' Trade Union Federation, which brought the people into the streets and called the general strike.

It acted after the government increased prices of essential commodities by up to 600 percent and imposed a 15 percent across-the-board sales tax.