CAIRO — Demanding an end to the “blood bath,” thousands of student protesters took to the streets of the Sudanese capital, Khartoum, and cities across the country on Tuesday, a day after four teenage demonstrators and an adult were killed in one of the deadliest episodes in months of unrest.

Sudanese protest leaders postponed scheduled talks with military leaders over plans to create a civilian government and they demanded an independent investigation into the killings, which occurred at a protest over bread and fuel shortages in the south-central city of El-Obeid.

Months of public pressure toppled Sudan’s longtime ruler, Omar al-Bashir, in April, leaving the country in the hands of a transitional military council. But negotiations to form a new civilian government, held against a backdrop of violence against protesters, have been troubled and have left the country in a precarious political state.

On Tuesday, protest leaders blamed a paramilitary group run by Lt. Gen. Mohamed Hamdan, the deputy chief of the military council, for opening fire on protesting high school students in El-Obeid, a city about 250 miles south of Khartoum.