MINSK, Belarus (AP) — Negotiators seeking a resolution of Ukraine's conflict have ended their latest session without obvious progress.

The so-called Contact Group consisting of representatives of Ukraine, Russia and the Organization for Security and Cooperation in Europe met Tuesday in the Belarusian capital Minsk, where an agreement was reached in February on a cease-fire and pullback of heavy weapons.

Although fighting reduced substantially after that agreement, both Ukraine and the separatist rebels it is fighting in the east claim daily violations. The war has killed more than 6,400 people since April 2014.

The Minsk meeting was to discuss the work of four subgroups, made up of rebel and Ukrainian representatives, which are focusing on political, security, humanitarian and economic questions.

Rebel representative Denis Pushilin said procedural differences troubled the talks.