The Israel Antiquities Authority began repair work on the Mughrabi Ascent leading to Temple Mount on Tuesday morning.
Police increased its presence in the area for fear that Muslim protesters would disrupt the renovation work.
Only women and men over 45 years old and holding Israeli identity cards would be allowed on the Temple Mount compound.
Last week, Khaled Mashaal warned Prime Minister Ehud Olmert against excavating in the Temple Mount, because this, according to Mashaal, would compromise the holiness of Al Aksa Mosque.
The IAA said the excavation was a salvage operation to install supporting pillars in the compound's archaeological garden to prevent structures from collapsing.