5 Ukrainian security forces killed despite ceasefire, army official says

Five Ukrainian security forces were killed and 25 were wounded in fighting with the separatists, Ukrainian defense spokesman Andriy Lysenko said.

He said at least 129 violations of the ceasefire have already taken place -- ranging from small arms fire to mortar attacks. But pro-Russian separatists have also blamed Ukraine for violations.

Dmytro Chalov, a spokesman for a sector of the Ukrainian army, said mortar fire pummeled the Mariupol area of eastern Ukraine.

The ceasefire went into effect more than 24 hours earlier, at midnight Saturday night.

Monday was slated to be a key day in the truce -- when both sides are supposed to withdraw heavy weapons. But neither has done so.

The Ukrainian army still has plans to pull heavy weapons out of the area, but it won't happen until the situation is quiet, Chalov said.

"We emphasize that our military will only fire in response," Lysenko told reporters Monday.

The ceasefire aims to end 10 months of fighting in eastern Ukraine. But less than 90 minutes after it started, Ukrainian officials reported mortar shelling at a military post near Zolote in the Luhansk region.Ukrainian President Petro Poroshenko has warned that if the separatists do not abide by the ceasefire, he will impose martial law throughout Ukraine.

Despite the reports of violence Monday, the truce did appear to hold up in many parts of eastern Ukraine. And that means some residents who have been holed up for weeks were able to venture out to buy food and medicine.

But the future remains uncertain.

"How long can this bloodshed go on for?" one woman told CNN. "All we want is peace."

(CNN)