Police in Armenia say that an unidentified assailant armed with a knife has taken a 3-year-old boy hostage at a pre-school.

Police said the hostage situation happened Monday in the town of Armavir, about 40 kilometers (about 25 miles) west of the capital, Yerevan.

Initial news reports from the ex-Soviet republic indicated that the attacker had taken all children and teachers hostage. But police spokesman Ashot Agaronian said the assailant was holding just one child, a 3-year-old boy.

Agaronian said the hostage-taker appeared to be driven by a personal motive, but he wouldn't elaborate.

The attacker posed no immediate demands, according to Agaronian.

It wasn't immediately clear how many children and teachers were at the pre-school at the time of the hostage-taking.