Fighting between Russia-backed separatists and government troops has killed over 9,500 people since it began in 2014 and left much of Ukraine's industrial heartland in ruins.
The U.N. Human Rights Office said in a statement on Wednesday that it documented 69 civilian casualties in eastern Ukraine in June, including 12 dead. This was nearly the double the number a month ago and the highest figure since August 2015.
International monitors have recently raised the alarm about both sides violating peace accords by using heavy weaponry that was supposed to have been withdrawn. Monitors of the Organization for Cooperation and Security in Europe last week recorded Grad multiple-grenade launchers in use there.