Graham Stack in Kyiv -

The ceasefire in East Ukraine's Donbas region between Ukraine government forces and Russian-backed separatist rebels is fragile but holding. Both sides reported some clashes but no fatalities on February 28 and March 1, and claimed to have withdrawn their heavy weaponry, though this is as yet unverified.

Reporting 17 breaches of the ceasefire on March 1, but also no casualties, spokesman for Kyiv's military operation Anatoly Stelmakh said that separatist forces were concentrated in the direction of Donetsk city, with eight cases of shelling of government troops or population centres on March 1. Acording to Stelmakh, there had been a clash between the two sides near the Ukrainian-held town of Avdeevka beside Donetsk, and an attack on Ukrainian positions on the outskirts of Luhansk. 

In a phone call with US Vice President Joe Biden on March 1, Ukrainian President Petro Poroshenko accused the pro-Russian rebels of violating the Minsk peace accords by "continuing artillery fire on the outskirts of Donetsk and Mariuopol", Ukraine's presidential administration said.

Earlier, a Kyiv military spokesman said that the night of February 28 had been quiet after some daytime shelling with eight injured but no known fatalities. Kyiv reported in the evening of February 27 that three government soldiers were killed over the previous 24 hours.

Kyiv's Stelmakh also said that Kyiv would complete the first stage of withdrawal of heavy weaponry from the line of separation between the two sides on March 1. This is in accordance with a ceasefire agreement negotiated by France, Germany, Ukraine and Russia in Minsk on February 11-12, which is now being monitored by observers from the Organisation for Security and Cooperation in Europe (OSCE). Ukraine's defence minister Stefan Poltorak said February 28 that weaponry with over 100mm caliber had already been removed from the frontline, according to Interfax.

Defence speaker for the rebels' self-proclaimed Donetsk People's Republic, Eduard Basurin, also said late on March 1 that the Donetsk rebels had completed the withdrawal of heavy weaponry from the demarcation line. The prime minister of the rebels' self-proclaimed Luhansk People's Republic, Gennady Tsipkalov, said the same for the Luhansk region, Interfax reported.

According to Ukraine's military, the rebels are attempting to deceive OSCE observers by drawing back heavy weaponry from the separation line, only to later move it forward again. Kyiv also claimed the rebels are regrouping in preparation for a new offensive.

The OSCE monitoring mission told Russian daily Kommersant on March 1 that it could not confirm the rebels' full withdrawal of weaponry. "We don't have the possibility to monitor the whole movement of heavy weaponry from start to finish. In some cases, mission members were not allowed to visit locations of heavy weaponry and the end points of their removal," an OSCE representative told the paper. The OSCE complained that both sides had failed to provide full information about their weaponry.

Ukraine's interior ministry reported it had detained over 50 people in the Ukraine-controlled port town of Mariuopol - the largest Kyiv-held town in the Donetsk region. The detainees were said to be former members of volunteer forces operating in the city in spring 2014, and had been arrested for armed robbery, kidnapping and illegal storing of arms.

The head of the Kyiv-controlled part of Luhansk region, Gennnady Moskal, reported that regular government troops had rounded up a “criminal” group of volunteer fighters from the irregular Aidar battalion of Ukrainian forces, led by a fighter with the code-name Filat. There was no mention of casualties in the hour-long firefight.

While ranged against the pro-Russian rebels, the Aidar group has recently turned against the authorities in Kyiv over plans for its disbandment. Moskal said its members had been preparing to destabilise the situation in Kyiv by force of arms. Aidar fighters previously clashed with police outside the Ministry of Defence building in Kyiv on February 2.