WASHINGTON (AP) _ The United States is concerned by the recent upsurge in terrorist bombings and shootings in Northern Ireland and Great Britain, the State Department said Wednesday.

Deputy spokesman Richard Boucher said the United States ''condemns in the strongest terms the violence, no matter what the source. This approach solves nothing but only breeds more violence.''

The incidents are widely believed to be part of a campaign by the Irish Republican Army to protest British policies in Northern Ireland. About 25 firebombs have been set off in Britain since Dec. 1.