Kiev - Seven Ukrainian health inspectors were injured Wednesday by a hand grenade thrown into their office, Korrespondent newspaper reported.

The blast took place in the Ukrainian capital Kiev shortly after midday.

The target, a branch office Ukraine's Sanitation and Epidemic Inspectorate near the Kiev central train station, suffered broken windows and smoke damage from the explosion.

The victims all received injuries "of varying degrees" from metal fragments and were hospitalised, the Interfax news agency reported.

Police said the weapon most likely had been a Soviet-era RGD-5 hand grenade. Law enforcers were searching for the bomber but two hours after the blast had not made public details on possible suspects.

No motive for the attack has yet emerged, but Ukraine's Sanitation and Epidemic Inspectorate is responsible for, among other duties, checking sanitation standards in food service businesses.

Kiev's last grenade attack came in April, after a explosive device hidden in a trash bin detonated in the central Shevchenko park, hospitalising two persons. (dpa)