The police detained a Ukrainian National Guard serviceman who shot five people dead and wounded five others at a military factory in the eastern Ukrainian city of Dnipro, Ukrainian Interior Minister Denys Monastyrsky wrote on Facebook Thursday.
The 21-year-old soldier opened fire at people inside a guard house of the Yuzhny Machine-Building Plant at about 4 a.m. local time (GMT 0200) for unknown reasons.
Four servicemen and one civilian woman were killed in the incident and five others were severely injured.
The Ukrainian authorities have launched a criminal investigation into the incident, the minister said.
The Yuzhny Machine-Building Plant produces launch vehicles, rocket engines, ballistic missiles and other products for the Ukrainian defense and aerospace sectors.