Sudanese teachers took to the streets of Khartoum on Tuesday to protest the death of a colleague in detention last week.
They were met with tear gas fired by the police as they rallied near the education ministry in the capital.
Ahmed al-Kheir, a 36-year-old teacher and member of the Islamist Popular Congress Party (PCP), died in detention after security agents arrested him last week in connection to the protests, a relative told AFP on Saturday.
Fellow teachers poured into the streets to chant for "freedom, peace, justice", a witness said, employing the rallying cry of the protest movement against Bashir's government.
"Many were carrying photographs of Kheir who died in detention," the witness added.
Kheir was a member of the PCP, which is part of President Omar al-Bashir's government but has called for a probe into the deaths of protesters killed during the rallies.
Police on Tuesday also fired tear gas at a separate demonstration launched by graduates of Khartoum University, witnesses said.
"The students were trying to stage a march, but they were dispersed with tear gas," a witness said.
Hundreds of doctors held sit-ins in several hospitals across the country calling on Bashir to step down, witnesses said.
Video footage uploaded onto social media showed doctors holding banners calling for Bashir's resignation.
About 200 lawyers held a separate march in Khartoum, but they were swiftly dispersed with tear gas, a lawyer said.
"We wanted to give a petition to the chief of the judiciary that calls for freedom of speech and the release of detainees," he told AFP on condition of anonymity.
"But riot police fired tear gas at us, after which we had to disperse."
The incident happened a week after Sudan's information ministry said the country's security chief had ordered the release of detained demonstrators.
There were no reports of any mass release of detainees.
What started as protests against price hikes on December 19 has quickly escalated into anti-government demonstrations calling on Bashir to resign.
Officials say 30 people have died in protest-related violence since then, but Human Rights Watch says at least 51 people have been killed.