After more than 6,800 deaths in the military conflict in eastern Ukraine since April 2014, the Ukrainian government and Russia-backed rebels say a much-anticipated ceasefire is holding. A truce brokered by Western powers in February helped to subdue the fighting but did not stop it completely.
Sept 1 is the first day of school in Ukraine and government troops and separatists agreed last month to implement the ceasefire by then.
In Kiev, Ukrainian presidential administration spokesman Oleksandr Motuzyanyk said they have not recorded any use of large-caliber weapons overnight despite sporadic use of rifles and grenade launchers. Motuzyanyk also said there were no casualties overnight.
In Donetsk, rebel leader Alexander Zakharchenko told Russian news agencies that troops did not attack their positions overnight.
The death toll from violent protests in Ukraine rose to two on Tuesday when another national guard officer died from injuries suffered in a grenade explosion, the interior minister said.
In the worst outburst of violence in Kiev since the new government took power in 2014, nationalist protesters clashed with police and national guard troops outside Ukraine's parliament on Monday as lawmakers took up a measure to give greater powers to Russia-backed separatists in eastern Ukraine.
About 140 people were hospitalized, most of them law enforcement officers, the interior ministry said. One national guard officer died on Monday, and a second died a day later, both as a result of injuries caused by the grenade, interior minister Arsen Avakov said.
Most of the 100 violent protesters were members of Svoboda, a nationalist party that holds only a handful of seats in parliament. Wielding truncheons, pipes and sticks with nails, they faced off against police carrying shields and truncheons.
About 30 protesters were detained, of whom 18 remained in custody on Tuesday, including the man suspected of throwing the grenade. Avakov said he was a Svoboda member who fought in the east in one of the volunteer battalions, which are loosely controlled by the government.
President Petro Poroshenko, on a hospital visit to see the injured officers, pledged to find the organizers of the clashes who were handing out sticks and weapons like grenades.
The decentralization of power was a condition demanded by Russia for a truce signed in Belarus in February aimed at ending the fighting between Ukrainian government troops and Russia-backed separatists that has left more than 6,800 people dead since April 2014.
But Ukrainian nationalists strongly oppose the constitutional changes, saying they would threaten the country's sovereignty and independence.
Poroshenko and his supporters insist that the constitutional amendment would devolve powers to local communities in all of Ukraine, from east to west, while making
sure that Ukraine stays a unitary state.
While Ukrainian nationalists think the amendment gives too much power to the regions including the east, Russia-backed rebels there say this is not enough.
Speaking to Russian news agencies in Donetsk, rebel leader Alexander Zakharchenko criticized Poroshenko for taking out a clause that could offer sovereignty to the
east and make it a part of a loose confederation within Ukraine.
Now that 265 lawmakers have given it preliminary approval, the bill comes up for the final vote where Poroshenko will need to get at least 300 votes.