A boy sits on a swing in Avdeyevka near Donetsk.
Children have been seen holding weapons at roadblock near to the port city of Mariupol. Pictured: A boy sits on a swing near his building, which was damaged during fighting between the Ukrainian army and pro-Russian separatists, as an armoured personnel carrier (APC) of the Ukrainian armed forces is seen nearby in Avdeyevka near Donetsk, eastern Ukraine, June 7, 2015. REUTERS/Gleb Garanich

Children have been seen holding weapons at a pro-Russian rebel roadblock near the embattled village of Shyrokyne, according to independent monitors observing the war in eastern Ukraine.

The revelation, which was announced by Michael Biocurkiw, a spokesperson for the Organization for Security and Co-operation in Europe (OSCE), during a press conference in Kiev late on Thursday evening, is symbolic of a conflict where rules, ceasefires and conventions have been broken on a daily basis, and where recent fighting between Ukrainian troops and pro-Russian rebels has reached levels not seen since the Minsk II peace deal was signed in February this year.

"During the most recent visit [to Shyrokyne], our monitors did spot what appeared to be underage children at that checkpoint,” said Biocurkiw. “This is the second time in recent times that we've seen children, and some of them [were] with arms.

"We're very concerned about observing this type of development – any time when children are involved in a conflict is unacceptable," he added.

Shyrokyne, which is only 10 miles from the strategic port town of Mariupol on Ukraine’s southern coast, has been the scene of deadly fighting for months. On Thursday morning, one soldier was killed and two injured in battles near the village.

There have been few days since the Minsk agreement went into force on Feb. 15 this year that the ceasefire and its conditions have been fully observed. Both sides have resorted to using banned heavy weapons, such as grad rockets and large artillery shells, and have regularly breached the line of contact since the war began in April 2014. During that time there have been no official reports of children holding weapons.

When questioned on the issue, Biocurkiw said that those “are only two [such] incidents in front of me, that we have seen” and that he and his team “will continue to gather as much information on this type of development as possible.”

Biocurkiw added that no one in the OSCE team communicated with the children at the roadblock.