A section of the ancient walls around the Old City of Kairouan collapsed on Saturday, killing three masons carrying out repairs on the Unesco world heritage site, Tunisian authorities said. In addition two workers were injured when a 30-metre (100ft) section of the 6-metre-high walls near the Gate of the Floggers crashed to the ground, the Civil Protection department said. “A team was carrying out restoration work” on the 3km (two mile) long wall that surrounds the Old City, department spokesperson Moez Tria told AFP, adding that the accident “could be linked to heavy rains in the area in recent days”. Founded in AD670, Kairouan is one of north Africa’s holiest cities and a leading tourist attraction. It has been listed as a Unesco world heritage site since 1988.