Italian coast guard has denied that it was slow to respond to the sinking of a boat carrying African migrants off the island of Lampedusa this week.
The accusations were made by a fisherman who took part in the rescue and a local newspaper.
So far, 111 bodies have been recovered, and 155 people survived, but about 200 are still unaccounted for.
High winds have prevented divers from reaching the boat, restricting rescuers to an aerial search.
France has called for an urgent meeting of EU states following the tragedy.
“European political officials must talk, and soon,” said French PM Jean-Marc Ayrault.
“It is up to them to meet to find a proper solution; compassion is not enough.”
Tens of thousands of migrants attempt the perilous crossing from North Africa to Sicily and other Italian islands each year, and accidents are common – but this week’s shipwreck was among the deadliest on record.
The survivors are to be placed under investigation for “clandestine immigration”, as provided for by a controversial immigration law pushed through by right-wing parties in 2002.
Italy has said it will amend immigration laws and has called for European help.
Italian members of parliament have complained that some of its provisions discourage people from helping migrants in distress.
The fisherman who arrived first at the site of the accident, Vito Fiorino, has accused the coast guard of wasting time by filming footage of rescue efforts.
“They refused to take on board some people we’d already saved because they said protocol forbade it,” Vito Forino was quoted as saying by Ansa news agency.
A report in local newspaper La Sicilia said two boats belonging to Italy’s Financial Guard, which carries out a range of police and rescue duties, had remained in port.
The coast guard denied that there was any delay in its rescue effort.
“After we received the alarm by radio at 07:00 we immediately intervened without boats, arriving on at the site of the shipwreck at 07:20,” it said in a statement.
Judicial authorities said they had no evidence of delays.
The head of a fishermen’s association, Toto Martello, denied in turn reports that three fishermen drove straight past the scene of the accident.
“The fishermen save lives,” he told Ansa.
“We rebut the accusations that we didn’t help people who were dying at sea.”
Other fishermen said there were so many migrant boat wrecks near Lampedusa that they damaged their nets every time they went out.
“Only now they become aware of this situation?” said Salvatore D’Ancona.
“It’s been 20 years that this is happening.”
The fishermen laid a wreath of flowers at sea, with some 10 fishing vessels blowing their horns for the victims.