SUDANESE security forces opened fire with tear gas on crowds of women in Omdurman on Sunday as they gathered in protest at the detention of women held during previous anti-government protests.

Hundreds took to the streets in defiance of threats by the Sudanese authorities, which have led a brutal crackdown on demonstrations calling for the resignation of autocratic Islamist dictator Omar al-Bashir.

They marched to the women’s prison in Sudan’s second city, demanding the release of those detained by authorities in Thursday’s huge protest in the capital Khartoum, chanting: “Long live the struggle of Sudanese women,” and “Down, that’s it.”

Demonstrators demanded the overthrow of Mr Bashir, who came to power in a 1989 coup, and insisted: “We are fighters, we will complete our mission,” as they marched to the prison.

Security forces moved in to make arrests and were seen dragging young women away in pick-up trucks as they fired tear gas to disperse the crowds.

Faiza Ibrahim Nugud, a member of the Sudanese Communist Party (SCP) central committee and in her eighties was among those arrested.

The rally had been called by the Sudanese Professionals Association (SPA), an umbrella organisation of trade unions and opposition groups that has led the growing anti-government movement.

The recent wave of unrest began when the government cut subsidies, leading to a tripling of the price of bread in December. However, anger over Mr Bashir’s handling of the economy has fed a broader protest movement.

Security forces have responded harshly, with more than 1,000 people — protesters, activists, opposition leaders and journalists — arrested since the protests began.

Rights organisations have said that more than 50 people have been killed, with authorities opening fire with live bullets on peaceful demonstrations.

And concerns are growing over the health and wellbeing of those who are being held in prison. Elderly prisoners, including two members of the SCP central committee, Fathi Fadhi and Ali Saeed, are reported to have been denied access to medical assistance, medicines or their families for over a month.

Doctors at the state hospital in El-Obeid, the capital of North Kordofan state, about 220 miles south-west of Khartoum, joined Sunday’s action with a protest, demanding Mr Bashir’s resignation.