BERLIN — Two people were killed and about 20 injured on Saturday in Münster, in western Germany, after the driver of a small truck crashed into a group of people in the heart of the old city, the police said.

The driver killed himself in the cab of the truck immediately after the crash, Andreas Bode, a spokesman for the Münster police said. “What led to the act is still fully unclear and we are investigating in all directions,” he said.

Police also said they were investigating what they identified as a “suspicious item” found in the cab of the truck, but declined to give any further details. They ordered all residents of the inner city and reporters at the scene to clear out while they were investigating the item.

Herbert Reul, the interior minister of the state of North Rhine-Westphalia, where Münster is, said the driver was a German citizen.