Sudan security forces arrest opposition leaders and activists in Khartoum

Sudanese security forces arrested about two dozen opposition leaders and activists as anti-government protesters sought to reach the presidential palace to deliver a petition calling for President Omar al-Bashir to step down.

Chanting "freedom, peace, justice", the protesters were confronted on Thursday in downtown Khartoum by riot police who fired tear gas at the crowd, witnesses told AFP and Reuters news agencies.

The activists were seeking to deliver a petition that demanded the formation of a transitional government to replace Bashir and his administration.

Rabah al-Mahdi from Sudan's main opposition National Umma Party said that at least 26 campaigners and opposition leaders were arrested, AFP reported.

The arrests come amid ongoing, near-daily protests across Sudan. First sparked on 19 December over the rising cost of bread, the demonstrations have since morphed into a countrywide call for Bashir's resignation.

More than 1,000 people have been arrested amid the unrest, while human rights groups say at least 51 have been killed. Sudanese officials put the death toll at 31.

On Thursday, al-Mahdi said the general secretary of the Communist Party, Mohamed Mokhtar al-Khatib, and three leading members of the Umma Party were arrested, as reported by Reuters.

The spokesman of the Sudanese Professionals' Association, the umbrella group that led the protest movement, was also detained, the news agency said.

Pressure on multiple fronts

So far, Bashir has resisted the widespread calls for his resignation, insisting that political change will only come through the ballot box.

He and some senior government officials have sought to temper public anger in recent weeks, pledging to release some of the detained protesters.

Still, the Sudanese government continues to face pressure on multiple fronts.

On Monday, almost 2,000 workers went on strike in Port Sudan in opposition to a privatisation deal for the city's key port, a main gateway for imports and exports to the country.

The government had hoped the deal would bring much-needed funds into the country, as spiralling inflation and crippling austerity measures have been a major source of resentment among Sudanese citizens.

Earlier this week, a United States official said the "excessive violence" used by Sudanese security forces to stem the protests may threaten talks aimed at removing Sudan from Washington's state sponsors of terrorism list.

While Washington lifted its trade embargo on Khartoum in October 2017, the country's continued place on the sponsors-of-terror list is viewed as a major obstacle to its economic recovery.

The US-Sudan negotiating process, "which could eventually lead to the lifting of state sponsors of terrorism designation ... is being threatened by the current developments", Cyril Sartor, senior director for Africa at the US National Security Council, told AFP on Wednesday.

"It is absolutely unacceptable for security forces to use excessive violence to crack down on demonstrators, to use detention without charge, certainly unacceptable to use brutality, torture ... and needless to say there's no reason anyone should be killed," Sartor said.