Sudanese security forces fired tear gas to disperse protesters trying to march on the presidential palace on Thursday amid nationwide demonstrations against October's military coup and a wave of political detentions.
The takeover ended a partnership between the military and civilian political parties, drawing international condemnation and plunging Sudan into political and economic turmoil.
Protests organized by neighborhood resistance committees have drawn hundreds of thousands of people, and at least 79 have been killed and more than 2,000 injured in crackdowns.
Hundreds of protesters diverged from planned routes on Thursday to renew efforts to march on the presidential palace but were met with tear gas and a heavy security presence a little more than a kilometer from their goal.
"We will continue demonstrating in the streets until we bring down military rule and bring back democracy," said Salah Hamid, a 22-year-old university student.
Other protests took place across the Nile in the cities of Omdurman and Bahri, and farther away in Gadarif and Sennar.
Sudan's long-standing economic woes have been exacerbated since last month by the blockade of the Northern Artery, a key route for trucks carrying exports from Sudan into Egypt.
That protest, originally against a rise in electricity prices for farmers, has expanded to reject military rule and demand more support for both farmers and traders. It also has trapped hundreds of Egyptian trucks in Sudan.
While some protesters in Khartoum said they were opposing a normalization of relations with Israel, which has been spearheaded by the military, others marched for the more than 2,000 people who lawyers say have been arrested since the coup. More than 100 remain in jail, one lawyer said on Thursday.
Two prominent political critics of the military, Khalid Omer Yousif and Wagdi Salih, were arrested on Wednesday.
Brigadier General Altahir Abu Haja, media adviser to military ruler General Abdel Fattah al-Burhan, said in a statement carried by state news agency SUNA that their arrests were not political and that investigations were continuing.
A prosecution statement said that Salih and others faced charges of breaking laws related to corruption, foreign currency and financial procedures.
The U.S. State Department said Washington, along with Britain, Canada, Norway, Switzerland and the European Union, "condemn this harassment and intimidation on the part of Sudan's military authorities."
"This is wholly inconsistent with their stated commitment to participate constructively in a facilitated process to resolve Sudan's political crisis to return to a democratic transition," it said in a statement, calling on the military to release all those unjustly detained and lift a state of emergency.