A batch of 834 pilgrims on Wednesday left a base camp here for the Kashmir Valley under tight security to undertake the annual Amarnath pilgrimage, officials said. The 39th batch comprising 614 males, 146 females, 67 seers and seven children left the Bhagwati Nagar base camp, in a convoy of 27 vehicles, for the twin base camps in Pahalgam and Baltal, between 3 am and 3.40 am, they said.