10.41pm BST

We're going to wrap up our live blog coverage for the day. Here's a summary of where things stand:

• Tensions ratcheted up in east Ukraine Thursday with at least one fatal clash between the Ukrainian military and pro-Russia forces, and dramatically increased Russian military activity on the Ukrainian border.

• US secretary of defense Chuck Hagel called the Russian military manoeuvres "dangerously destabilizing" and "very provocative." Kiev asked Moscow for an explanation "within 48 hours."

• The Ukrainian military resumed operations in the east Thursday, moving in troops and vehicles and battling with separatists for control of an arms depot and at least one checkpoint outside the city of Slavyansk. There were conflicting reports of fatalities on the militia side.

• Russian president Vladimir Putin called the Ukrainian military action a "serious crime" and said there would be "consequences." The Russian foreign ministry said Washington "must compel the current Ukrainian leadership to immediately cease military operations in the south-east."

• More than one recent scheduled phone conversations between US secretary of state John Kerry and Russian foreign minister Sergey Lavrov has been canceled, Moscow said. Kerry was expected to speak on the crisis later Thursday evening.

• Read our latest news story here.