ANKARA

The OSCE has condemned violations of the cease-fire along the line of contact in eastern Ukraine in recent days and expressed "serious concern" over the use of proscribed heavy weapons.

The OSCE Chairperson-in-Office, Serbian Foreign Minister Ivica Dacic said a press conference in Belgrade on Sunday said fighting was increasing in and around Donetsk and Shyrokyne.

Dacic repeated the OSCE’s call “to all sides to fully and unconditionally respect the cease-fire, end all hostilities and implement all provisions from the Minsk Agreements, including the withdrawal of heavy weapons”.

“At this moment, it is essential for the political process to gain momentum, and I call all sides to invest all possible efforts towards that end,” he said.

Dacic repeated his full support for the activities of the Special Monitoring Mission to Ukraine (SMM) and stressed the importance of their safety and security.

 He recalled that several incidents over the May 1-2 period placed them in potentially dangerous situations in eastern Ukraine.

A cease-fire was signed between Ukrainian forces and pro-Russian separatists in Minsk on Feb. 12, which included the withdrawal of heavy weaponry from combat areas and release of all hostages and unlawfully detained persons.

Both sides have accused each other continuously for violating the cease-fire.

Ukrainian and European leaders have accused Russia of fueling the conflict by providing arms and ammunition to the separatists, a claim Russia denies.

Moscow accuses the U.S. and the EU of deliberately destabilizing Ukraine to expand the West's military presence in Eastern Europe through NATO.

Since April 2014, more than 6,000 people have lost their lives in the conflict between Ukrainian forces and pro-Russian separatists, according to the United Nations.