A 27-year-old Syrian who blew himself up outside a crowded music festival on Sunday was facing deportation to Bulgaria, a German interior ministry spokesman said on Monday.

"Syrians cannot at the moment be deported to Syria at the moment, but that doesn't mean that Syrians overall cannot be deported," Tobias Plate told a regular government news conference.

"The Syrian in Ansbach was facing deportation and this was to Bulgaria," he said.

A government spokeswoman told the same news conference that it was too early to decide on changes to Germany's refugee policy before the results of the investigation into the attack were published.

"The acts of the last days and weeks do not show a uniform picture," said Ulrike Demmer. "Most terrorists who carried out attacks in Europe over the last months were not refugees."