Sightseeing visits were barred at Germany’s landmark Cologne cathedral and Christmas Eve worshippers faced security checks to get into midnight Mass on Sunday as police responded to indications of a potential attack. However, a top security official urged people not to shy away from holiday celebrations out of fear.

Churchgoers attended multiple services at the cathedral despite the ban on visits purely for sightseeing, a day after police descended on the cathedral and searched it with sniffer dogs.

In Austria, police in Vienna also said they were stepping up security around churches and Christmas markets, apparently responding to the same intelligence about a potential threat. They did not give further information but the dpa news agency reported without citing a source that the threat was from an Islamic extremist group.

Police in Cologne said they were taking precautions over Christmas even though the information they had was for an attack on New Year’s Eve.

“Even if the reference was to New Year’s Eve, there are a lot of people in the area around the cathedral, today is Christmas Eve midnight Mass, it is one of the most visited cathedrals, the main train station is nearby,” said police spokesman Wolfgang Baldes, standing in front of the cathedral. “There are a lot of people and that’s why we said that if there was an indication we would do everything necessary to protect people.” Cathedral Provost Guido Assmann said in an interview on the Cologne archdiocese website domradio.de that sightseeing visits had been stopped but that didn’t mean a big change since such visits are normally not allowed during services anyway and services were being held throughout the day Sunday.

Cologne’s towering cathedral, whose twin spires rise 157 metres (515 feet) high, is a major tourist destination visited by some 6 million people a year. 

It is home to the Shrine of the Three Kings, a gold- and silver-decorated casket said to contain the relics of the three wise men described in the New Testament as paying homage to the newborn Jesus.

Police and cathedral officials urged those attending Mass on Sunday evening to arrive early and not bring bags or purses.

Herbert Reul, interior minister for the state of North Rhine-Westphalia, appealed to the public not to stay away. “Caution is advised,” he said, but “we are not defenceless. Our agencies are using all available information to protect us as well as possible.”

“My appeal is, go to church, celebrate Christmas. Fear is the currency of terrorists. We should not make it more valuable.”

 The European Union’s home affairs commissioner, Ylva Johansson, warned on Dec 5 that Europe faces a “huge risk of terrorist attacks” over the Christmas holidays due to fallout from the war between Israel and the Palestinian militant group Hamas.