The international talks underway to calm tensions in Ukraine didn't deter armed pro-Russian separatists who took over this Ukrainian tv control tower.

They used it to tune in to and transmit Russian tv stations in the Ukrainian city of Slaviansk.

In the same city another group of separatists continued their occupation of a local administration building.

On the same day the U.S., Ukraine, European Union and Russia reached agreement on calming tensions.

A joint statement issued after talks in Geneva called on all sides to refrain from violence, intimidation and provocative action.

But U.S. Secretary of State John Kerry warned of more sanctions if Russia failed to act.

(SOUNDBITE)(English) U.S. SECRETARY OF STATE JOHN KERRY SAYING:

"We fully expect the Russians, as they said they would here today, to demonstrate their seriousness by insisting that pro-Russian separatists ,who they've been supporting, lay down their arms, leave the buildings and pe