A fresh batch of 2,224 pilgrims left here on Tuesday amid tight security to take part in the ongoing Amarnath Yatra, an official said. "The yatris left the Bhagwati Nagar Yatri Niwas at 3.35 a.m. in an escorted convoy of 85 vehicles for the Kashmir Valley," he said. So far, more than 2.15 lakh devotees have performed this year's Amarnath Yatra that started on June 29, and will end on August 7, on 'Shravan Purnima' coinciding with the Raksha Bandhan festival. Situated at 3,888 metres above the sea-level, the cave shrine houses an ice stalagmite structure that waxes and wanes with the size of the visible moon. Devotees believe the structure symbolizes mythical powers of Lord Shiva. Over 35,000 security personnel drawn from the Army, Central Reserve Police Force (CRPF), Sashastra Seema Bal (SSB), Indo-Tibetan Border Police (ITBP) and the state police have been deployed for the security of the pilgrims. Eight pilgrims were killed and 16 were injured when terrorists attacked a yatra bus at Batengo in Anantnag district on the Srinagar-Jammu highway on July 10. Another 17 pilgrims were killed and 27 were injured on July 16, when a bus carrying pilgrims plunged into a gorge by the same highway in Ramban district.