In a key test of the U.N. peacekeeping force-ability to take command in southern Lebanon, Norwegian troops yesterday barred an Israeli patrol from entering a Lebanese village near the Golan Heights.

Witnesses said the Norwegians refused to allow the Israeli Army unit to pass through a U.N. checkpoint at Hebbariyeh, three miles west of the Israeli-occupied Golan Heights, and that after an argument, the Israelis turned back.

It was the first such incident involving Israeli troops and U.N. peacekeeping forces since the U.N. entered southern Lebanon two weeks ago.

U.N. officers disclosed, however, that a similar test of their authority - this time involving Palestinian forces - occured last Saturday at a French roadblock between the Palestinian and Israeli lines five miles south of the port city of Tyre.

A U.N. officer said the Palestinians fired on the roadblock with machine-guns and rocket-propelled grenades, but stopped shooting when the French returned the fire.

Meanwhile, a token force about 100 Lebanesa security police arrived at Tyre in a small, but significant first step in reasserting the Beirut government's authority in south Lebanon for the first time in two years.

The Lebanese forces joined French U.N. troops at checkpoint around Tyre, and one group took up positions at the Kakia Bridge over the Litani River in the central sector, Lebanese officials said.

In Beirut, Palestinian commandos claimed responsibility for the death yesterday of an Israeli soldier who was shot as he was thumbing a ride in East Jerusalem. Passing automobiles have been hit previously by faming gasoline bottles in the area, near the Rockefeller Museum.

Later yesterday, an Arab youth was shot to death in almost the same spot, and an Israeli Civil Defense guard was arrested for questioning in connection with the shooting. The Israelis rushed security reinforcements into the Old City of Jerusalem when hundreds of Arab youths demonstrated against the shooting.