Ukraine's government

The Organization for Security and Cooperation in Europe (OSCE) says it has lost a contact with one of its monitoring teams in Ukraine.

Four monitors operating in the southeast of the country have not been accounted for since 18:00 local time (16:00 GMT) on Monday, according to the BBC.

The observers performing a routine mission.

Ukraine's government has announced it is ready to engage in talks with parties and regional representatives in the east, where unrest has been ongoing for weeks.