A popular tourist boat sank in the British city of Liverpool on Saturday, local media reported.

The amphibious Yellow Duckmarine vessel carrying more than 30 people, including children, went under at Liverpool's Albert Dock on Saturday afternoon.

Passengers were thrown into the water and either had to be rescued or swim to safety, according to local reports.

No one was seriously hurt, and an investigation has been launched into the incident.

It is the second sinking incident in three months for the yellow vehicles, local media said.