Armed men seized the capital of a Russia-backed separatist republic in eastern Ukraine amid a power struggle between two top officials.
The takeover of Luhansk on Tuesday followed a decision by Igor Plotnitsky, the head of the breakaway Luhansk People's Republic, to fire interior minister Igor Kornet the night before.
Luhansk state television showed masked men with assault rifles and heavy machine guns blocking the entrances of administrative buildings and streets in the centre of Luhansk on Tuesday, reportedly on the orders of the interior ministry. One of them wore the blue uniform the interior ministry's Berkut unit, a police force specialising in putting down riots.
The armed men had ignored Plotnitsky's command to leave, Russian independent newspaper Novaya Gazeta reported.
A video on Tuesday evening showed what appeared to be dozens of military vehicles entering Luhansk from the direction of the neighbouring Donetsk separatist republic, although a Donetsk official denied it was intervening.
In a video on Tuesday Kornet said he wanted to “dispel rumours” of his dismissal and said his forces had captured Ukrainian saboteurs who were attempting terrorist attacks in the republic.
He also claimed that Plotnitsky's chief of staff and the head of the security service had been implicated in a coup attempt last year and arrested on Plotnitsky's orders, along with the general director of the state television company.
But Plotnitsky later said in a statement on his website that Kornet had indeed been fired and the actions of interior ministry forces “crossed all acceptable lines”. He said the “attempts of certain people to remain in power” were futile and “will be completely neutralised in the near future”.
The outcome of the power struggle remained unclear on Tuesday. Novaya Gazeta reported that the republic's state security ministry, military headquarters and people's militia were “not participating in the conflict between Plotnitsky and Kornet”.
Separatists seized control of much of the Luhansk and Donetsk regions in April 2014 following the establishment of a pro-Western government in Kiev and Russia's annexation of Crimea. The ensuing conflict between the rebels, who have received military assistance from neighbouring Russia, and government forces has claimed more than 10,000 lives.
A ceasefire agreed in Minsk in 2015 has been regularly violated, and a Ukrainian soldier died in a mortar strike on Monday. Several top separatist commanders have been assassinated since the start of the conflict.