Authorities in Sudan's restive South Kordofan province have declared a month-long state of emergency after the fatal shooting of four people at a bus station on Monday.
Officials said four others were injured in the shooting in provincial capital Kadugli.
Activists working for fairer treatment of rural residents identified the four who were killed as between the ages of 27 and 40. They said they were members of the Moro tribe that inhabits the Nuba mountains, site of a long-running civil war.
No group had claimed responsibility for the attack by early on Tuesday evening.
Sudanese media reports said the victims had been on their way to areas controlled by rebels of Sudan People's Liberation Movement-North when the shooting took place. They quoted witnesses as saying the assailants opened fire with AK-47 assault rifles at a tea house at the bus station where the victims had been sitting.
The assailants remain at large, said the activists, but Kadugli was calm on Tuesday.
Provincial governor Moussa Gabr said the shooting was “unfortunate and bitter” and vowed the authorities would do everything to restore security and stability in the area.
"We have been dealing with incidents like these. Our society will be in danger if these attacks continue," he said. The state of emergency came into effect on Monday and the heads of districts in the province will decide whether to impose a curfew in their areas, he added.
"We will not rest until we restore security and stability in the province and the feeling of security for its residents," said Mr Gabr.
The activists told The National that Monday's shooting followed a foiled attempt a week ago to kidnap a member of Kordofan's ancient Salateen aristocracy and a series of kidnappings on the road between Kadugli and Deling, also in South Kordofan.
One of the activists, Nizar Abdullah, blamed a recent proliferation of firearms and the worsening economic situation for the surge of violence in the area.
"The incident alarmed the government because there has been a rise in violence in recent weeks and months," he said.
"This scenario will happen again because of the proliferation of arms and tribal clashes. The local government swiftly declared a state of emergency so it can have the power to contain the violence."
Another activist, Mohammed Ismail, recounted a recent incident in the area in which gunmen tried to free about 20 death-row inmates when a police vehicle taking them to a prison in Obeid in North Kordofan came under attack. The attempt failed but the police driver was killed.
"What happened is simply a reflection of the weakness of the government and its security agencies," he said.
The Sudan People’s Liberation Movement-North, led by veteran rebel Abdel Aziz Al Hilu, controls large parts of the province, including the Nuba mountains.
It has been fighting the government for decades for what it says is a fair distribution of national wealth and to end the monopoly on power by an Arabised Muslim elite in northern Sudan.
A ceasefire was declared between the military and the group after the fall of Sudanese leader Omar Al Bashir in 2019 after 29 years in power. However, tension arose between the two sides following the derailment of the country's democratic transition by a military takeover in October 2021.
Critics of the military contend that the October 2021 coup has created a political and security vacuum that permitted a resurgence of ethnic and tribal violence in Sudan's "fringe" regions, such as Darfur in the west and Kordofan and Blue Nile in the south.
The coup also plunged the Afro-Arab nation into its worst economic crisis in living memory, with western powers suspending billions of dollars' worth of desperately needed aid and debt forgiveness to protest against the military takeover. They say they will resume aid only when a credible democratic transition led by a civilian government is in place.