Authorities in Cologne, Germany, said Thursday that the annual Women’s Street Carnival had begun peacefully.
The carnival, which precedes the Christian observance of Lent and runs until Ash Wednesday on February 10, starts with the traditional "Weiberfastnacht" festivities, a day when women symbolically take charge of the city.
The carnival also includes street parties, song and dance, and alcohol consumption by costumed revelers. Organizers have urged them to report any harassment to security personnel.
Police have doubled the number of officers on hand compared with last year to more than 2,000. They were on alert to prevent a repeat of a shocking string of sexual assaults during New Year's celebrations.
Hundreds of women in Cologne were groped and robbed by a mob of mostly North African and Arab men as the city rang in 2016.
Around 1,000 complaints have been filed over the crime spree, which has ignited an intense debate about Germany's ability to integrate the 1.1 million asylum seekers it took in last year.
In preparation for the carnival, police coordinated closely with their federal counterparts, fire and rescue units and others.
Closed-circuit television cameras were installed and bans were imposed on known petty thieves, including suspected pickpockets who took part in the crime spree on New Year's Eve.
A "security point" for women was set up, staffed by social workers and psychologists, and the local judicial system geared up to accelerate the processing of offenders during the festivities.
IS suspects arrested
Elsewhere, police arrested at least two Algerians suspected of having links to Islamic State.
Police made the arrests in the capital, Berlin, and at a refugee home in the western town of Attendorn. The arrests were part of an investigation of four people, two of whom were not detained.
A Berlin police spokesman, Stefan Redlich, said the four men were suspected of being connected to Islamic State and at least one of them was sought by Algerian authorities on suspicion of being an Islamic State member and receiving training in Syria.
The men were suspected of planning an attack "threatening the security of the state," according to police.