Seven Ukrainian soldiers were killed and seven wounded when they were ambushed by pro-Russian separatists near the eastern Ukrainian town of Kramatorsk, the Ukrainian defence ministry said.
It was the biggest single loss of life by the Ukrainian army since soldiers were sent into the mainly Russian-speaking east of the country to break up armed separatist groups who have seized control of towns and public buildings to push their demands for autonomy.
The ministry, in a statement published on its website, said an armoured column came under fire as it approached a bridge near a village 12 miles from Kramatorsk, one of several hot spots in the region.
About 30 rebels, who had taken cover among bushes along a river, attacked with grenade-launchers and automatic weapons, immediately killing two soldiers and wounding three others.
“In all, as a result of the prolonged fighting, six members of the armed forces were killed. Eight soldiers were wounded, one of them seriously,” the statement said.
The state security service said later that the seriously wounded soldier had died while being transported to hospital.
Before the Kramatorsk incident, the Ukrainian Defence Minister Mikhail Koval said a total of nine servicemen had been killed so far in the army’s “anti-terrorist” operation, which has been directed mainly against rebels in the towns of Slovyansk and Mariupol. The dead included five pilots who died when their helicopters were shot down.
Meanwhile Russia responded to Western sanctions against its activities in Ukraine by saying it would refuse to co-operate with the US in the International Space Station.
The Deputy Prime Minister Dmitry Rogozin said Moscow would reject a US request to prolong the orbiting station’s use beyond 2020, and bar Washington from using Russian-made rocket engines to launch military satellites.
Moscow took the action, which also included suspending operation of GPS satellite navigation system sites on its territory from June, in response to US plans to deny export licences for hi-tech items that could help the Russian military.
“We are very concerned about continuing to develop hi-tech projects with such an unreliable partner as the United States, which politicises everything,” Mr Rogozin told a news conference.
Washington wants to keep the $100bn, 15-nation space station project in use until at least 2024, four years beyond the previous target.
While six years away, the plan to part ways on a project which was supposed to end the “space race” underlines how relations between the former Cold War rivals have deteriorated since Russia annexed Ukraine in March.
Since the end of the US Space Shuttle project, Russian Soyuz spacecraft have been the only way astronauts can get to the space station, whose crews include both Americans and Russians.
Mr Rogozin said Moscow was planning “strategic changes” in its space industry after 2020 and aims to use money and “intellectual resources” that now go to the space station for a “project with more prospects”. He suggested Russia could use the station without the United States, saying: “The Russian segment can exist independently from the American one. The US one cannot.”
The US space agency Nasa is working with companies to develop space taxis with the goal of restoring US transport to the station by 2017, but the US currently pays Russia more than $60m per person to fly its astronauts up.
In addition to the hi-tech sector sanctions, the US and the EU have imposed visa bans and assets freezes on officials and politicians and targeted companies with links to President Vladimir Putin.
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