Ukraine crisis: US backs claims of Russian tanks in eastern Ukraine

The United States has backed claims by Ukraine's government that tanks being used by separatists in the east of the country came from Russia.

Russia has denied the claim but a US state department spokesperson told the media that tanks and rocket launchers had crossed into the country from Russia in the last three days.

Meanwhile Ukraine is still in dispute with Russia over its unpaid gas bill.

Alpa Patel reports.