It has been suggested the total may be a record
The Italian coastguard says around 4,000 people have been rescued from the Mediterranean Sea as tens of thousands of migrants continue to flee Libya for Europe.
Commander Cosimo Nicastro suggested the total may be a record, although around 4,400 migrants were pulled from unseaworthy boats in the region in one day in August last year.
Some 20 bodies were spotted in the sea.
Elsewhere, a Libyan navy spokesman said 766 migrants were rescued by the Libyan coastguard. Colonel Ayoub Gassim said 550 were found near the coastal city of Sabratha and 216 off Zwara.
Photos tweeted by the European Union's Mediterranean mission showed a blue dinghy submerged under the weight of migrants, none of whom had lifejackets, trying to attract the attention of the aircraft.
Today's rescues follow the dramatic capsizing of an overloaded migrant boat off Libya on Wednesday that led to the deaths of five passengers.
Vivid images released by the Italian navy showed migrants desperately clinging to the vessel as it overturned while others swam towards life jackets thrown by navy crew.
A report by Interpol last week rclaimed that another 800,000 migrants in the lawless north African country are waiting for an opportunity to make the journey to Europe.
The study claimed smugglers organised in loosely connected networks continue to facilitate migrants' passage to Europe and that the annual turnover of migrant smuggling was more than US$5bn (€4.46bn) in 2015.
The migrant crisis is preoccupying world leaders at this year's G7 summit in Japan. Donald Tusk, president of the European Council, said the EU is seeking more support for the creation of refugee resettlement schemes.
"Those who criticise us should rather think how to increase their assistance because what Europe provides is already massive," he said.