Col. Valentin Fedichev, deputy commander of the anti-rebel offensive, said on Saturday that Ukrainian forces were finishing their withdrawal in time for Saturday's deadline. The aim is to create a secure 50-kilometer (30-mile) buffer zone between the rebels and Ukrainian military.

The headquarters of Kyiv's eastern military operations said on its Facebook page on Friday that all the Uragan multiple rocket launchers had been pulled back from their positions, following the withdrawal of smaller systems, such as Grad missile launchers.

'Pretending'

Rebel official Denis Pushilin also said on Saturday that pro-Russian separatists had completed their pullback ahead of schedule. Defense minister of the self-proclaimed separatist Donetsk People's Republic Eduard Basurin, said that some mortars which weren't even covered under the agreement had also been pulled back.

There has, however, been no independent confirmation of either side's claim. Despite both sides saying they are complying with the pullback of heavy weapons, they have also accused each other of only pretending to do so.

The security headquarters in Ukraine-controlled Mariupol accused the rebels in a statement of pulling back their equipment only to "return it shortly thereafter."

Basurin was also quoted by Russian agencies as saying that Ukraine was carrying out "covert rotation" of its forces.

Observer increase

Following a discussion with French, German and Russian officials in Berlin on Friday, Ukraine also agreed to double the number of observers from the Organization for Security and Cooperation in Europe (OSCE) in the country's conflict-ridden east - ramping up its size to 1,000 observers.

More than 6,000 people have been killed in the conflict.

ksb/sms (AP, AFP, dpa)