A roadside mechanic who witnessed the accident told Channels Television that a school bus filled with children narrowly escaped the explosion.
Another witness said the tanker driver was driving at a very high speed when he lost control and veered off the road, hitting a culvert with the vehicle said to be carrying about 3,000 litres of diesel and burst into flames on impact.
Fire trucks of the Lagos Fire Service reportedly arrived early on the scene, but exhausted their supply of water without putting out the fire.
It took the arrival of a second fire truck to extinguish the flames.
The incident, which occurred on Monday, is said to have caused a massive gridlock on both sides of the expressway.