Human Rights Watch (HRW) has urged Ukraine to stop using unguided rockets which it said have killed at least 16 civilians in several recent attacks.
The rights watchdog said that both Ukrainian troops and pro-Russian separatists have used Grads -- unguided rockets fired in salvos and sprayed across a wide area -- in the conflict in eastern Ukraine.
HRW warned that using such weapons in populated areas could amount to war crimes.
Kyiv has denied using Grads around major cities.
But HRW said investigations into four attacks between July 12 and 21 in insurgent-held Donetsk "strongly indicates that Ukrainian government forces were responsible for" firing the Grads.
It also accused insurgent forces of having recently used such rockets.
HRW's statement came after the Red Cross declared that Ukraine is in a civil war -- an official distinction that would allow warring parties to be prosecuted for war crimes.
With additional reporting by AFP