Mbh 7.173.1b

Then Karna of sure aim, contending with vigour, afflicted those mighty car-warriors among the Panchalas with his shafts like a cloud pouring torrents of rain upon a mountain. The Panchala host, thus afflicted by Karna, fled away in fear, like a doe frightened by a lion. Horsemen were seen falling from their horses, and elephant-riders from their elephants, O monarch, and car-warriors from cars, all around. In that dreadful battle, Karna cut off with razor-faced arrows the arms of flying combatants and heads decked with car-rings. And he cut off, O king, the thighs of others that were on elephants or on the back of steeds, or on the earth, O sire! Many mighty car-warriors, as they fled away, felt not their loss of limbs or the injury in their animals, in that battle. Slaughtered by terrible shafts, the Panchalas and the Srinjayas took the motion of even a straw for Karna (so great was their fright). Deprived of their senses, the warriors took their flying friends for Karna and fled away from these in fear. Karna pursued the broken and retreating host, O Bharata, shooting his shafts on all sides. Indeed, in that battle, the retreating warriors, deprived of their senses, were slaughtered with mighty weapons by that illustrious hero, Karna. Others, only looked at by Drona, fled away on all sides. Then king Yudhishthira, beholding his army flying away, and regarding retreat to be advisable, addressed Phalguna and said, “Behold that mighty bowman, Karna stationed there like Rudra himself armed with his bow. Behold him scorching everything around like the blazing sun himself, at this fierce hour, this dead of night. These wails are being incessantly heard, O Partha, of thy helpless friends who are uttering them, mangled by the shafts of Karna. The manner in which Karna is aiming and letting off his shafts is such that no interval can be noticed between the two acts. He will, O Partha, annihilate all our friends.