In a mass collision on the A1 near Elsdorf in Lower Saxony, eleven cars drove into each other.
According to police information, 24 people were injured on Saturday afternoon.
A seriously injured and a slightly injured pregnant woman were taken to hospitals, the police added in the evening.
"All other victims are likely to have suffered minor injuries," it said.
The Autobahn was completely closed from the Bockel junction in the direction of Hamburg.
The closure should last for hours, as the police announced in the early evening.
According to the information, a driver had lost control of his vehicle around 3:13 p.m. in heavy rain.
He went off the road.
As a result, heavy traffic caused a kilometer-long traffic jam, it was said.
At around 3:50 p.m., more than ten cars collided at the end of the traffic jam near the Elsdorf junction.
The investigators estimated the damage to property at around 100,000 euros.