Under heavy police guard, Israeli workers began a dig Tuesday at a centuries-old walkway in Temple Mount, a holy site disputed by Muslims and Jews, a spokesman said. Palestinians warned this week that work just outside the site, would inflame already high tensions. Muslims fear that Israel is planning to damage the neighboring hilltop compound, the third-holiest site in their religion. Israel's Antiquities Authority said it is building a new pedestrian ramp leading up to the compound, which has been the scene of clashes in the past. The original earthen walkway was damaged in a snowstorm three years ago. Police spokesman Shmuel Ben-Ruby said police were stationed in alleys throughout the Old City and at the entrances to the disputed compound "to thwart any attempt to disrupt order." Police also restricted access to the site. Only women and men over 45 years old and holding Israeli identity cards would be allowed on the Temple Mount compound. The authority's work Tuesday entailed digging at the ramp to ensure that the renovation work does not damage any archaeological artifacts found at the site, officials said. "We have begun the work in preparation for the salvage dig that is supposed to start here in the coming days in the framework of the renovation of the Mughrabi Bridge," Yuval Baruch, the Antiquities Authority's chief archaeologist for the Jerusalem region, told Israel Radio. As work got under way, there were no immediate reports of unrest. Muslims believe the hilltop compound is where the Prophet Muhammad ascended to heaven. The compound houses Al-Aksa mosque and the Dome of the Rock shrine. Jews revere the compound as the site of their two ancient temples. When Israel opened a tunnel alongside the compound in 1996, it sparked clashes that killed 80 people. In 2000, then-opposition leader Ariel Sharon visited the site. The next day, riots erupted, beginning years of violence.