KIEV, April 5 (Xinhua) -- Ukraine will heighten security measures for its state-run defense enterprises after a grenade attack against one of them, the country's defense conglomerate Ukroboronprom said Thursday.

According to the statement on the Ukroboronprom website, Ukraine's research and production complex Photoprylad in the central Cherkassy region was attacked with grenades earlier in the day.

Unknown attackers hurled two grenades at Photoprylad's production department at about 2:05 a.m. local time Thursday (2305 GMT on Wednesday), and one of them has exploded, the statement said.

There were no casualties in the incident.

Located in Cherkassy city, some 200 km southeast of Kiev, Photoprylad produces weapon-aiming and fire-control systems, as well as night vision devices for the Ukrainian army.

The government-run Ukroboronprom unites more than 130 enterprises from various sectors of Ukraine's defense industry.