A landmine explosion in eastern Ukraine claimed the lives of three teenagers on rebel-controlled territory, the mayor of the town of Horlivka, Ivan Prikhodko, said on Sunday.

"They found an abandoned house and were just looking for adventure," Prikhodko said. "We are constantly confronted (by the problem of mines) and I think it is something that will continue for some time," he added.

The boys, aged 13 to 15, accidentally stepped on the mine in the region that has seen heavy fighting since the conflict between Kyiv forces and the pro-Russian rebels escalated in 2014. The blast injured the fourth child, a ten-year-old boy, who is being treated in hospital for shrapnel injuries.

The information was confirmed by the one of the separatist leaders, Denis Pushilin, and Eduard Basurin, the defense head of the "Donetsk People's Republic."

All four of the children were students at a school in Horlivka, a separatist-controlled town some 30 kilometers (18 miles) north of the frontline.

Read more: Is peace in eastern Ukraine doomed?

Watch video 03:36 Share Crossing borders on the way to school in Donbas Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/34nLQ Crossing borders on the way to school in Donbas

Rebels and Kyiv forces agreed on a truce in late August to allow children in the disputed areas to attend school. However, the deal was shaken when a bomb blast in downtown Donetsk killed the leader of the rebel-controlled entity, Alexander Zakharchenko. The separatists have blamed Ukraine's "operatives" for the hit.

On Saturday, three people were injured in another Donetsk blast, including a candidate for Zakharchenko's post.

Over 10,000 people have died in the east Ukraine conflict.

dj/jm (Reuters, dpa, AFP)

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