Officers forcibly carried off dozens of demonstrators who had staged a sit-in to try to stop the work outside Barzilai Hospital in the southern city of Ashkelon. Police spokesman Micky Rosenfeld said 15 protesters were arrested.

Archaeologists have determined the graves belonged to Christians or pagans from the Byzantine period, about 1,400 years ago. But ultra-Orthodox Jews insist they are Jewish bones that should not be moved, in accordance with religious practice.

A fence surrounding the hospital was topped by barbed wire to keep out demonstrators, and police set up checkpoints at the entrances to the city to ward off any major inflow of protesters.

The operation, which got under way after weeks of political wrangling, took place under the guard of hundreds of police deployed in the area in anticipation of possible violence.

But ultra-Orthodox rabbinical leaders did not call for a major protest, Deputy Health Minister Yaakov Litzman told Israel Radio.

After the graves were discovered, Israel's Cabinet — under pressure from ultra-Orthodox coalition members — voted to relocate the planned facility. But Prime Minister Benjamin Netanyahu reversed that decision.

Ashkelon is not far from the Gaza Strip, and doctors had warned that if Palestinian militants again fire rockets at the city, the trip between the hospital and a separate emergency room would be dangerous.

The relocation also would have cost millions of dollars.