A Norwegian unit of the U.N. peacekeeping force was locked in a tense confrontation with Israeli troops in southern Lebanon Tuesday, U.N. sources said.

Elsewhere in southern Lebanon, four Lebanese villagers were killed and four wounded when Israeli gunners shelled Shiite Moslem guerrilla hideouts in Tibnin valley before dawn, police said.U.N. sources said Norwegian and Israeli troops faced each other through the night, fingers on triggers, as flares illuminated the skies over the foothills of Mount Hermon.

The source said the tension developed after Norwegian peacekeepers blocked Israeli troops two days ago from setting up a checkpoint close to a Norwegian outpost on the southern edge of Hebbariyeh.