German police warn of possible attack at Cologne Cathedral

German authorities said that have received an alert that a group may be planning an attack on the Cologne Cathedral, the DPA news agency reported Saturday.

Authorities have not elaborated on the alert they received, saying police in the German city will take special protective measures.

Sniffer dogs were brought in to search the premises after the evening mass service, and visitors will be screened before entering the church, Michael Esser, the chief of police, said in a statement.

Esser said that even if the alert were for New Year's Eve, authorities would "take everything into account this evening to ensure the safety of cathedral visitors on Christmas Eve."

Police said late in the morning that no arrests had been made in connection with the possible attack, according to the German Press Agency (dpa).

The German daily Bild reported that officials in Germany, Austria and Spain had  received indications that an Islamist group was planning several attacks in Europe.

Authorities in Cologne have recommended visitors avoid carrying bags or arriving too early for mass at the church.

Millions visit church every year

The Cathedral, the largest Gothic church in northern Europe, was designated a UNESCO World Heritage Site in 1996. It attracts millions of visitors every year.

The construction of the church began around 1248 and was completed in 1880.

It withstood the bombing of Germany during World War II and has been hailed as a symbol of postwar reconstruction.

rm/jsi (Reuters, dpa)