Moscow, Feb 26 (IANS/RIA Novosti): The deputy director of a Russian military shipyard has been hospitalised with head injuries following a beating by unidentified attackers.

The incident took place in the northern city of Severodvinsk, police said.

Eduard Baal, who works at the Zvyozdochka shipyard near the White Sea, was attacked at his apartment building after returning from work late Friday, but the incident was revealed only Monday.

"He has a brain concussion and numerous bruises on his body," the regional interior ministry said.

The attackers were allegedly armed with unspecified metal objects, police said. The motive for the attack was not clear.

Baal, who was temporarily standing in for his boss on the day of the attack, is in a satisfactory condition, plant spokesman Yevgeny Gladyshev said.

A criminal investigation has been started into the crime.

The Zyozdochka plant focuses on repairs of submarines, civil and military ships as well as scrapping obsolete nuclear submarines. It also has a gem-cutting department.