The coastguard conducted two rescue operations off the city of Garabulli, 60 kilometres (40 miles) east of Tripoli, spokesman Colonel Abu Ajila Abdelbarri said.
He added that patrols had found 31 bodies and 60 survivors from one boat, along with a further 140 survivors from a second.
'When we arrived at the spot, we found an inflatable dinghy with several people clinging to part of it,' he said. He did not specify whether any people had been reported missing. 'The weather conditions these days are favourable for sending migrants to European shores on boats that are often unseaworthy,' he added.
Libyan patrol boat commander Nasser al-Ghammoudi said one of the vessels was three-quarters under water when the coastguard arrived. 'We looked for other survivors for more than five hours,' he said. 'We were able to rescue one woman after we heard her shouts.'
Other rescue operations were ongoing on Saturday evening, Italian coastguard told AFP. Italy's coastguard, which coordinates the rescue effort in international waters, reported that a total of 1,500 people had been saved on Thursday and Friday.
The large numbers of recent days contrast with the sharp drop since mid-July in the number of migrants being brought to Italy.
On Thursday, the UNHCR put the number of arrivals at Italian ports in the previous three months at 21,666, the lowest total registered in four years for that period of the year.
The downward trend has been attributed to a controversial combination of an Italian-led boosting of the Libyan coastguard's ability to intercept boats and efforts to enlist the help of powerful militias to curb traffickers' activity.
There have also been moves to tighten Libya 's southern borders, accelerate repatriations directly from Libya and measures to stem the flow of migrants from sub-Saharan Africa through transit states such as Niger and Sudan.
Those rescued by Libyan coastguard on Saturday were brought back to a naval base in Tripoli where the authorities provided them with water, food and medical care.
UN human rights chief Zeid Ra'ad Al Hussein in mid-November labelled as 'inhuman' European Union support for Libyan authorities to intercept migrants in the Mediterranean and return them to 'horrific' prisons in Libya .
Last week, US television network CNN aired footage of an apparent slave auction in Libya where black men were presented to North African buyers as potential farmhands and sold off for as little as $400 (350 euros).
Libya 's UN-backed unity government said it would form a 'commission to investigate these reports in order to apprehend and bring those responsible to justice'. People trafficking networks have flourished in the chaos that followed a NATO-backed uprising which toppled long-time dictator Moamer Kadhafi in 2011.
The unity government has said Libya is 'a victim of illegal immigration, a transit state, not its source', adding that the only solution is a return to stability.
Tunisian migrant influx
back under control: Italy PM
The influx of Tunisian migrants crossing the Mediterranean to Italy is back under control after a spike in numbers at the end of summer, Italian Prime Minister Paolo Gentiloni said Saturday.
'After some problems over the course of the summer, the accord started to work very effectively again,' he told reporters in Tunis, referring to a six-year-old agreement between the two countries aimed at curbing illegal immigration.
According to the International Organization for Migration, 1,357 Tunisians reached the Italian coastline between January and August, a number which jumped to more than 1,400 in the month of September alone.
Migration has become a burning issue in Tunisia since October 6 when around 40 people were killed in a collision between a migrant boat and a Tunisian navy vessel.
Migrants use small vessels headed for the Italian islands of Sicily and Lampedusa.
The Tunisian Forum for Economic and Social Rights said in a report last year that half of Tunisian youths from low-income areas were thinking of leaving the country, and one in three was prepared to do so clandestinely. The NGO said increasing poverty and unemployment in the North African country were to blame.