A blast occurred not far from the Polish memorial site at Lychakivske cemetery in Lviv, western Ukraine on late Tuesday.
The explosion took place at about 9.50 p.m. local time, Mykhailo Nagay, the director of Lychakivske Cemetery Museum said.
According to the local security guard, an unknown item lay on the ground not far from the memorial. There are no victims or any damage to the memorial or the tombstones.
The Polish memorial was opened in 2005 to honor the memory of Polish warriors who fought against the-then Western Ukrainian People's Republic and against the Soviets in 1918-1920. These soldiers were buried in the Graveyard of Lviv Defenders, part of the Lychakivske Cemetery.