Russia says a temporary ceasefire remains in effect in honor of Orthodox Christmas but Ukraine argues the truce is a hoax as Russian attacks continue in the country's east.

Russian President Vladimir Putin ordered a 36-hour ceasefire starting Friday.

Governor Pavlo Kyrylenko of Ukraine's eastern region of Donetsk says fighting continued overnight. He wrote in a social media post on Saturday that Russian attacks killed two civilians in central and northern Donetsk.

Ukraine presidential adviser Mykhailo Podolyak tweeted that the essence of the Russian truce is to "kill in the back, imitating silence."

The British defense ministry said in its intelligence update on Saturday that fighting has continued "at a routine level" into the Orthodox Christmas period. It said, "One of the most fiercely contested sectors continues to be around the town of Kremina, in Luhansk."

In a message for Orthodox Christmas, Putin praised the Russian Orthodox Church for supporting Moscow's forces fighting in Ukraine. He said their "massive, complex and truly selfless work deserves sincere respect."

He was apparently aiming to rally support for his military operation through the church which has great influence over Russian society.