"162 security troops have died since 18:00 (local time, 16:00 GMT) on September 5", Vladislav Seleznev said.
The spokesman said earlier that clashes had wounded some 300 servicemen, including 12 hospitalized with serious injuries.
On September 5, Kiev and eastern Ukrainian pro-independent militias agreed on a ceasefire in the Belarus capital Minsk, but ever since then the opposing parties have repeatedly accused each other of violating this agreement.
This was followed by Kiev's announcement on December 9 of a unilateral "silence regime" in a bid to renew ceasefire talks with independence supporters, but also to give the government troops time to recover. Independence supporters upheld the peace initiative, saying there had been no deaths after the lull in fighting was declared.
The current ceasefire was expected to be followed by a meeting of the Contact Group, comprising representatives of Kiev, independence supporters, Moscow and the Organization for Security and Co-operation in Europe on December 12, which was later postponed until Sunday.
The United Nations estimates that more than 4,700 people died and over 10,000 were wounded in the eastern Ukrainian armed conflict over the past nine months, with 1,357 killed dying since the truce was announced in September.