Two regions in eastern Ukraine where government and separatist forces have been fighting since 2014 were hit by more than 1,400 explosions on Friday, monitors for the Organization for Security and Cooperation in Europe (OSCE) said, pointing to a surge in shelling.
The two Russian-backed, self-proclaimed republics in Ukraine's Donetsk and Luhansk regions are at the centre of a surge in tensions between Moscow and the West over a vast Russian military buildup near Ukraine.
The OSCE's Special Monitoring Mission that is deployed in the conflict zone said it had logged 553 explosions in Donetsk.
A further 860 were reported in neighbouring Luhansk. Both numbers were valid as of 1630 GMT on Friday, it said in a statement released late on Saturday.
The monitoring mission confirmed one civilian casualty in a government-controlled area of Donetsk.
It put the total number of ceasefire violations on Friday at more than 1,500 compared with 870 the day before when monitors reported 654 explosions.
(Reporting by Maria Kiselyova and Anton Zverev; Editing by Tom Balmforth and Mark Potter)