The accident happened on National Highway 1, which links the capital with the interior of the country and is often heavily congested
At least 18 people were killed in a collision between a minibus a lorry in western Gabon on Saturday, the government said in a statement.
Pictures said to be from the crash scene, shared on social media, showed bloody and dismembered bodies.
The accident happened near the town of Kango, 100 kilometres (60 miles) from Libreville, along a stretch of the country's main highway.
"The tragic provisional toll is 18 dead," transport minister Ernest Mpouho Epigat said, adding that bodies of the victims had been taken to the capital.
The cause of the collision was unknown and an inquiry has been opened, the government statement said.
Road accidents are frequent in Gabon, a Central African nation of 1.8 million inhabitants.
The government urged road users "to observe the elementary tules of road safety," especially during the current busy holiday season,
The National 1 highway, where Saturday's accident happened, links Libreville with the interior of the country and is often heavily congested.