Pirates have been causing havoc in one of the world's busiest shipping lanes, hijacking dozens of ships last year and demanding tens of millions of dollars in ransom payments.
Hamburg-based ship operator Bernard Schulte Shipmanagement confirmed the hijacking. It said no ransom demands had been made.
"The master was briefly allowed to communicate with us and it appears that all crew members are safe," it said in a statement.
Piracy in the Gulf of Aden has prompted some shipping firms to take an alternative route via South Africa instead of via the Suez Canal.
The alternative shipping route has lowered the frequency of hijackings, but there have still been three boats captured this month.
The German military reported there were two more suspected attempts by pirates to attack ships in Gulf of Aden on Thursday.