At least six CRPF jawans were injured when unidentified militants today opened fired on their convoy on Srinagar-Jammu national highway in south Kashmir's Anantnag district. br br Militants fired at a CRPF bus, which was part of a convoy on way to Jammu from Srinagar, near Green Tunnel at Samthan in Bijbehara, 50 kms from here, a police officer said.