The city’s morgue presented another chilling site — the remains of a man whose wrists had been bound and whose torso had bullet wounds. The attendants at the morgue said the man had been executed while helpless.

Who he was, and who had killed him, was not immediately clear. Colonel Qaddafi’s forces have been credibly accused of executing detainees during the uprising. But on Saturday, journalists for The New York Times observed a man accused of being a Qaddafi agent being summarily executed by rebels at Ajdabiya’s northeast checkpoint.