Russia's security services shot dead four inmates on Friday who had taken hostages at a jail in Volgograd and fatally stabbed four of its staff.
"Snipers of the special forces of the Russian National Guard in the Volgograd region, with four precise shots, neutralised four prisoners who had taken prison employees hostage. The hostages have been released," state news agency RIA quoted the National Guard as saying.
The federal prisons service said all four attackers had been "liquidated". It said four of its staff had died of stab wounds, and others had been treated in hospital. A total of eight prison employees and four convicts had been held hostage, it said.
The operation to free the captives took place after President Vladimir Putin, addressing a weekly meeting of his Security Council, said he wanted to hear from the interior minister, FSB security chief and head of the National Guard about the incident.
The demands of the hostage-takers were not clear, though in rambling monologues they said that Russia "oppresses Muslims everywhere" and that they had acted "without mercy" in response to alleged mistreatment of Muslim prisoners.
Russian news media said the four were citizens of Tajikistan and Uzbekistan, and that three were in jail for drugs offences and the other for murdering someone in a fight.
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Israeli planes and tanks pounded the eastern and northern outskirts of Gaza City overnight Saturday to Sunday, destroying buildings and homes, residents said, as Israeli leaders vowed to press on with a planned offensive on the city.
The Pentagon is working on plans to deploy the US military to Chicago as President Donald Trump says he is cracking down on crime, homelessness and undocumented immigration, the Washington Post reported on Saturday.
Thousands of Australians joined pro-Palestinian rallies on Sunday, organisers said, amid strained relations between Israel and Australia following the centre-left government's decision to recognise a Palestinian state.
North Korean leader Kim Jong Un supervised the firing of new air defence missiles to test their combat capability, state media KCNA reported on Sunday.