There have been daily confrontations between Palestinians hurling rocks and Israeli police using stun grenades since the detectors were placed at the entrance to the shrine - known to Muslims as the Noble Sanctuary and to Jews as Temple Mount - on Sunday, after the killing of two Israeli policemen.
Muslim leaders and Palestinian political factions have urged the faithful to gather for a "day of rage" against the new security policies, which they see as changing delicate agreements that have governed the holy site for decades.
The Israeli police said extra units had been mobilised to bolster security in the Old City, while Muslim access to the shrine for prayers would be limited to women of all ages and men over 50. Roadblocks were in place on approach roads to Jerusalem to stop buses carrying Muslims to the site.
"Police are coordinating to enable Friday prayers to take place and at the same time security measures are taking place," spokesman Micky Rosenfeld said.
The Noble Sanctuary-Temple Mount compound, containing the Dome of the Rock and the Aqsa Mosque, has long been a source of religious friction. Since Israel captured and annexed the Old City, including the compound, in the 1967 Middle East war, it has also become a symbol of Palestinian nationalism.
On Thursday, there were calls for Netanyahu to back down and remove the metal detectors so as not to inflame the situation.
