Huge crowds of costumed revelers took to German streets on Thursday as the much-loved Carnival celebrations got underway, with the two Rhineland Carnival bastions of Cologne and Düsseldorf a focus of the merrymaking.

The Carnival revelries, which will continue until Ash Wednesday (this year on March 5), are this year being monitored by police even more cautiously than usual amid reported threats circulated on social media, though Germany's Federal Criminal Police Office (BKA) said none was particularly credible.

The heightened security also comes after a number of attacks on the public in recent months, including in the western German city of Solingen, in Aschaffenburg in the south and, most recently, in the Bavarian capital of Munich.

Cologne police step up security

Although the BKA called the threats "propaganda publications," police in the state of North Rhine-Westphalia, where both Cologne and Düsseldorf are located, are taking the issue seriously.

Police in Cologne said the situation was "more tense than in previous years" and announced they were stepping up security with 1,500 more officers, 300 workers from the department for public order and 1,200 private security staff.

Barriers were also to be set up to protect against car-ramming attacks, while officers will carry out more knife checks.

Cologne police chief Johannes Hermanns said Thursday that there had so far been no major security incidents in the city center.

"From the police's point of view, the situation has been very calm up to now. The city is quite full, but there are far fewer people on the streets than last year," he told the daily local Kölner Stadtanzeiger.  

Carnival encouragement

A spokesman for the Düsseldorf police also said there would be a bigger police deployment than in previous years.

State Interior Minister Herbert Reuls said altogether 9,900 police officers would be on duty in the state on Thursday.

However, in a speech marking the day, Cologne Mayor Henriette Reker encouraged revelers to be undeterred by the threats, some of which reportedly were made by the terror group "Islamic State" (IS).

"We won't let terrorists or Islamists take away our sense of life. We can count ourselves lucky that we have the Fastelovend," she added, using the word in local dialect for Carnival.

The celebrations culminate on Rose Monday (this year on March 3) with thousands of people dressing in costumes and gathering on the streets for parades in large cities and small villages alike throughout the Rhineland region.

Neckties in danger

According to German Carnival tradition, the Thursday before Shrove Tuesday is called Weiberfastnacht (roughly "old maids" day).

On the day, women are permitted to symbolically take control in the Rhineland where the two cities are situated, demonstrating their power by cutting neckties off men — a decades-old practice that is declining amid a growing lack of that clothing item.

The Weiberfastnacht tradition of allowing women to take command dates back to the Middle Ages in what was then a radical upending of conventional gender roles.

Edited by: Sean M. Sinico