Several people suspected of planning attacks during the holidays have been arrested in Austria and Germany, German newspaper Bild reported, as quoted by AFP.

German police announced on Saturday night that they were searching the Cologne Cathedral (west of the city) with the help of dogs after a “danger warning” was issued on New Year’s Eve, writes News.ro.

“Although the information relates to New Year’s Eve, starting this evening we will do everything in our power to ensure the safety of visitors to the cathedral on Christmas Eve,” Cologne police chief Michael Esser was quoted as saying in a statement.

After the evening service and “with the agreement of the head of the cathedral guard,” the cathedral was searched with the help of special dogs trained for this purpose, the police reported.

“On Sunday, all visitors will be checked before entering the place of worship,” the message reads. “The police recommend people not to have bags with them and to come to the service earlier,” he added.

German daily Bild reported on its website that security services in Austria, Germany and Spain had received indications that the Islamist group was planning new attacks in Europe, possibly in the run-up to the New Year and Christmas.

According to the newspaper, Christmas services in Cologne, Vienna and Madrid could be the targets of these attacks.

In the evening, police in Cologne and Vienna said they were stepping up security measures due to a possible threat.

The newspaper also claims that the first arrests made by the special forces took place on Saturday in Vienna, as well as one in Germany.

According to the German news agency DPA, the Islamist group could be linked to the terrorist group “Islamic State of Khorassan”, which operates in Central and South Asia.