A coastguard patrol plucked 87 migrants of different African nationalities, including six women and a child, from a sinking rubber boat about 50 kilometres (30 miles) east of the Libyan capital. They were taken to a Tripoli naval base, said navy spokesman Ayoub Kacem.
In a separate mission, some 203 migrants including a woman and also all from African countries, were spotted on board two boats off the coast of the town of Zliten, some 140 kilometres east of Tripoli. They were taken to a detention centre in Suq al-Khamis.
UN agencies and aid organisations have opposed taking migrants to camps in Libya, which has been wracked by chaos since the overthrow of longtime dictator Moamer Kadhafi in 2011, amid fears they will find themselves in arbitrary detention, or fall victim to militias.
Their already precarious situation has worsened since strongman Khalifa Haftar launched an assault on Tripoli on April 4, seeking to capture the city where the internationally recognised government is based.
More than 75,000 people have been driven from their homes in the latest fighting and 510 have been killed, according to the World Health Organization.
More than 2,400 have also been wounded, while 100,000 people are feared trapped by the clashes raging on the capital's outskirts.
In 2017, Italy reached a deal, backed by the EU, to train and equip the Libyan coastguard in a bid to stop the flow of migrants seeking to reach Europe from Africa across the Mediterranean.