A former rebel chief in eastern Ukraine who has lost his job in a sudden reshuffling has attributed his downfall to unspecified "intrigue."

Andrei Purgin said Wednesday he had spent four days under arrest at the local security agency headquarters in the rebel-held city of Donetsk before being released. He refused to discuss the reasons behind his arrest and dismissal from being speaker of the separatist parliament.

Some observers see Purgin's dismissal as part of Moscow's efforts to bring the rebel leadership to heel to observe a February peace deal.

The Minsk accord, brokered by Germany and France, requires Ukraine and the rebels coordinate on holding local elections, but the rebels have set a vote for October without reaching agreement with Kiev. Ukraine and the rebels have blamed each other.