The Ukrainian city of Donetsk was rocked by blasts on Saturday, even as government forces and pro-Russian separatists prepared to create a buffer zone to separate the warring sides.
A memorandum signed early on Saturday calls for the withdrawal of heavy weapons, including artillery, and all foreign fighters from a 30 kilometer-wide buffer zone.
A Reuters correspondent in Donetsk, the main industrial hub in Ukraine's turbulent east, said several powerful explosions were heard in the morning. A plant producing munitions and industrial explosives had been hit, municipal authorities said.