BELFAST, Northern Ireland (AP) _ A bomb hidden in van exploded in a town southwest of Belfast, injuring a police officer and shattering nearby shop windows, police said.

Several elderly residents of Banbridge, about 25 miles southwest of Belfast, were hospitalized for shock following the Thursday blast, neighbors said.

A spokesman for the Royal Ulster Constabulary said the police officer was also hospitalized with leg injuries.

There was no immediate claim of responsibility.

Sectarian violence has plagued Northern Ireland, where the Irish Republican Army, supported by a minority of Catholics, has been fighting British rule. Protestant paramilitary groups have attacked suspected IRA members.

The bomb, hidden inside a red van, exploded outside the town's courthouse, the constabulary said. Police received a warning call 15 minutes before the explosion, but not everyone was alerted.

One was 15-year-old shopgirl Mary McEvoy, who was behind a newspaper counter about 200 yards away.

''It was terrifying. Most of the glass was blown out and we were hit by some,'' Miss McEvoy said. ''We were told nothing and I saw a number of people running about wondering what was happening. No one was told anything.''