Ukraine’s leaders appear to have backed away from threats to use force to crush pro-Russian protests in the country’s eastern regions amid reports that elite anti-terror commandos refused to storm the buildings seized by the protesters.

The deadline set by Kiev for the protesters to free the occupied government offices in Donetsk and Lugansk expired on Friday morning, with security forces making no attempt to storm the buildings. Acting Interior Minister Arsen Avakov had earlier pledged to clear the buildings within 48 hours.

According to Ukrainian media reports, the elite Alfa counter-terrorism group has refused to attack the protesters.

“We will act strictly according to law,” Alfa commandos were reported to have said. “Our group has been set up to free hostages and combat terrorism.”

Acting Prime Minister Arseniy Yatsenyuk promised to grant more powers to the regions, including the right to hold local referendums.

“In the framework of the changed constitution, we will be able to satisfy specific requests of every single region,” Mr Yatsenyuk said at a meeting with the governors and other officials of Ukraine’s eastern and southern regions in Donetsk on Friday.

Mr Yatsenyuk did not spell out details of the proposed reforms and his vague promise is unlikely to mollify the protesters. The Ukrainian government plans to unveil the new constitution on April 15, but it has flatly rejected the protesters’ demand of federalisation of Ukraine.

Mr Yatsenyuk refused to meet with the protesters during his one-day visit to Donetsk on Friday but promised to have a televised call-in conference with its residents.

The protesters in Donetsk, Lugansk and Kharkiv initially demanded self-rule for Ukraine’s eastern industrial heartland, but after Kiev rejected their demands, they vowed to split from Ukraine and join Russia through a referendum similar to the one held in Crimea last month.

Acting President Oleksandr Turchynov has offered immunity from prosecution for hundreds of protesters holed up in government offices in Donetsk and Lugansk if they clear the seized buildings but the activists refused to climb down. On Thursday they received reinforcements from local coal mines.

Russia’s Foreign Minister Sergei Lavrov said that Russia has no plans to annex Ukraine’s southeastern regions.

“We do not and cannot have such ambitions. This would go against Russia’s fundamental interests,” Mr Lavrov said in a TV interview on Friday.

“We want Ukraine to be united in its current borders, but with full respect for its regions. We call it federation, but we do not insist on using this term. The main thing for Ukraine is to carry out a constitutional reform with the participation of all its regions and to hold presidential, parliamentary and local elections on this basis, so that the regions elect their own legislatures and governors,” the Russian Foreign Minister said.

He expressed the hope that Mr. Yatsenyuk will honour his promise of reforms.

“It’s a good thing Yatsenyuk has visited the southeast… He should have done it much earlier, as we’ve been telling your American and European partners,” Mr Lavrov said.