United Nations Middle East envoy Nickolay Mladenov warned on Monday that a solution was needed by Friday to the Jerusalem Al-Aqsa mosque crisis, which threatens to have "potential catastrophic costs well beyond the walls of the Old City."

"It is extremely important that a solution to the current crisis be found by Friday," he told reporters after briefing the U.N. Security Council behind closed doors.

Tensions have escalated since Israeli occupation forces closed Al-Aqsa Mosque for two days last week and installed metal detectors at entry points.

Six Palestinians were killed by Israeli troops in clashes in east Jerusalem and the West Bank and hundreds injured since Israel attacked worshippers outside Al-Aqsa following Friday prayers.

Three Israeli settlers were killed by a Palestinian man on Friday evening.

"The dangers on the ground will escalate if we go through another cycle of Friday prayer without a resolution to this current crisis," Mladenov said.