German police say they've arrested a second person in connection with the detention last week of a Syrian asylum-seeker who was suspected of planning to carry out an attack.

Police in the western city of Duisburg said the man was arrested Wednesday in nearby Dinslaken, but gave no further details.

A day earlier, authorities said that a 24-year-old Syrian was arrested last Friday in Mutterstadt, in a neighboring German state, after an unidentified witness provided information on possible plans for an attack.

North Rhine-Westphalia state's interior ministry said there was "no concrete threat situation."