Large vessels were prevented from entering Germany's Kiel Canal that connects the North Sea to the Baltic due to a software problem, a spokesperson for the shipping authority said Sunday.

"We had to interrupt traffic for safety reasons. Our colleagues are trying everything to solve the problem as quickly as possible," the Kieler Nachrichten daily quoted Detlef Wittmüss, head of the Kiel Canal Waterways and Shipping Authority, as saying.

By the early afternoon, smaller ships were able to enter the canal again in Brunsbüttel, on the North Sea side. Later in the day, small vessels should also be able to resume their journeys in Kiel on the Baltic side, the spokesperson said.

Normally, about 70 to 80 ships used the Kiel Canal on Sundays.

In recent days, new software had been installed to control navigation on the artificial waterway, the spokesperson said. It had initially worked without a glitch.

On Sunday morning, however, problems arose, making it impossible to steer larger ships.

Technicians were in the process of fixing the issue, but it was unclear how long that would take.