MINSK, Belarus (AP) — The United Nations says the number of civilian casualties in the conflict in eastern Ukraine has surged in the past three months.

Fighting between Ukrainian government troops and Russia-backed separatists has killed more than 10,000 people since 2014. Hostilities have subsided since both sides signed a truce in 2015 but sporadic fighting persists and no progress has been made towards a political solution.

The U.N.'s Office of the High Commissioner for Human Rights said in a report published Wednesday that 12 civilians were killed and 93 injured between mid-May and mid-August, which is 30 percent more than in the previous three-month period.

The U.N. said it lays the blame both on Moscow and Kiev for the uptick in hostilities.