It has been reported that it was a water truck rigged with explosives which caused the bombing.
Witnesses have said residents were ferrying victims to Misrata hospitals in ambulances and cars, many with shrapnel wounds and some bodies too damaged to be identified.
Medical sources had initially said 65 people had been killed, including some civilians. But Fozi Awnais, head of the crisis committee for the health ministry in Tripoli, said later that 47 people had died and 118 more were wounded.
Libyan media said the attack struck the al-Jahfal training camp, a military base during the rule Muammar Gaddafi. Mayor Miftah Hamadi said the bomb detonated as around 400 recruits were gathering in the early morning.
“It was horrific, the explosion was so loud it was heard from miles away,” Hamadi told Reuters by telephone.
“All the victims were young, and all about to start their lives.”
A country in chaos
Since a NATO-backed revolt overthrew Gaddafi in 2011, suicide blasts and car bombings have increased as Islamist militants have taken advantage of the country’s chaos to expand their presence.
It is currently run by two rival governments – only one of which is recognised internationally – and a range of armed factions locked in a struggle for control.
Islamic State militants have grown in strength, taking over the city of Sirte and launching attacks on oilfields. Islamic State fighters this week attacked two major oil export terminals.
The Zliten blast is the worst since an attack in February last year when three car bombs hit the eastern city of Qubbah, killing 40 people. That attack was claimed by the so-called Islamic State group, just a few months after it established a foothold in the country.
The latest explosion has not been officially claimed by any group yet, but it comes against the backdrop of intensified attacks this week carried out by IS militants near Libya’s eastern oil ports.