In one incident, an animal crashed through the windows of a hotel.

Another kept a group of scientists trapped in their offices for an hour, while several more animals were spotted on a beach.

Correspondents say the boar may have been chased from their natural habitat when a bush area was cleared for construction.

Unexpected guest

Hotel staff at the region's coastal resorts may be used to the occasional difficult guest.

But receptionists at the Hotel Ambasador were not prepared for the appearance of a wild boar weighing 100 kilograms (220 pounds) when it arrived in the lobby late on Monday.

It was a living nightmare

Daniela Zagarliuc hotel manageress

The animal had sauntered in from the beach and was followed by two startled life guards, witnesses say.

"It was a living nightmare," hotel manageress Daniela Zagarliuc told the Associated Press news agency.

She said her seven-year-old son, who was playing in the reception at the time, fainted at the shock.

The boar was also scared by the commotion it had inadvertently caused and escaped through the window, leaving a trail of blood.

Meanwhile another wild boar kept scientists at the Maritime Research Institute in Mamaia trapped for nearly an hour.

On spotting the beast in the grounds of the institute, the scientists locked the doors and refused to come out until a member of the local hunting association shot the animal dead.

Wild boar are considered dangerous to humans when hurt or cornered.