Blue, white and black tarps covered the bodies at the port.
Coast guard ships, local fishing boats and helicopters from across the region were combing the waters trying to find survivors, said coast guard spokesman Marco Di Milla.
The boat left from Tripoli with migrants from Eritrea, Ghana and Somalia, Di Milla said.
Antonio Candela, the government's health commissioner for Palermo, said 159 people had been rescued, but the boat is believed to have been carrying as many as 500 people, the LaPresse news agency reported.
