By Jihed Abidellaoui, Zohra Bensemra and Khalil Ashawi NABATIEH, Lebanon, June 26 (Reuters) - Chanting rhythmically in the summer sun, the men marched through the southern Lebanese city of Nabatieh as part of their annual tradition to mark Ashura, the holiest day in the Shi'ite Muslim calendar. This year, they walked through a city in ruins. Israel's nearly four-month air and ground campaign that it says was targeting armed group Hezbollah has destroyed large swathes of Lebanon's south and left other parts of it under Israeli military occupation.