KIEV, Ukraine (AP) — A cease-fire in east Ukraine is being upheld by both government troops and Russia-backed rebels, a senior Ukrainian official said Tuesday, in a first step toward enforcing a truce that has been riddled by repeated violations since it was imposed earlier this month.

Col. Andriy Lysenko, spokesman for Ukraine's National Security and Defense Council, told journalists that the cease-fire had been upheld since late Monday, making it the first night in weeks that there have been no civilians killed or residential buildings shelled.

Lysenko said there also had been no casualties among Ukrainian forces.

Russia-backed rebels in east Ukraine said they were pulling back heavy artillery from front-line positions in response to similar moves by the Ukrainian army. Those maneuvers are part of a new peace agreement signed Saturday, which requires both sides to remove heavy artillery from the front line, creating a buffer zone that would allow the cease-fire to be more effectively enforced.

Rebel leader Alexander Zakharchenko told Interfax news agency Tuesday that his forces were withdrawing heavy artillery from certain areas on the front line, but said that "in those places where Ukraine does not withdraw its artillery, we also will not withdraw."

In the largest rebel-held stronghold of Donetsk, the city council said in a statement published online early Tuesday that one resident had been killed by shelling Monday evening, but that overnight and on Tuesday morning the city was calm.

In Zhdanivka, a village just 20 miles (35 kilometers) northeast of Donetsk that until recently was under Ukrainian control, residents told the Associated Press that government troops had withdrawn two days ago.

The neighboring village of Nyzhnya Krynka, which is slightly closer to Donetsk, was still under rebel control, but there was no sign of heavy artillery weapons in the area. The scars of war, however, are still visible in the village, which was caught in the crossfire of heavy shelling between the Ukrainian and rebel sides in recent weeks.

Five bodies could be seen in a mass grave near a local mine. Another mass grave was dedicated to the rebels: their bodies weren't visible but four gravestones, wreathed with flowers, were engraved with the epitaph: "They died for Putin's lies." It appeared to be an expression of anger at the Russian government, led by President Vladimir Putin, for not assisting the rebels further.

Ukraine and the West say Russia has provided personnel, arms and expertise to the rebel forces, a claim Moscow denies.