Tense standoffs between pro-Russian activists and the Ukrainian authorities are continuing in eastern Ukraine.

In the city of Luhansk 51 people held against their will have been released from a state security building but activists are still occupying it.

In Kharkiv there have been clashes with police as protesters demanded their fellow pro-Russian colleagues be set free after earlier being arrested.

And in Donetsk activists have remained inside a regional authority building.

In all three cases the call is for a referendum to be held on secession from Ukraine.

Kyiv claims the occupations are part of a Russian-led plan to break up the country.

Meanwhile international efforts are being stepped up to try and diffuse the crisis. The United States, the European Union, Russia and Ukraine have agreed to meet next week offering a glimpse of possible diplomatic progress in the conflict.