Angela Merkel talks tough: Cologne mass attacks on women planned, says justice minister

"When such a horde meets to commit crimes, it seems to have been planned in some way. Nobody can tell me that it wasn't coordinated or pre-prepared," Maas told the German newspaper Bild.

Maas was also not prepared to rule out a connection between the Cologne attacks and the other attacks on women in other German cities that happened on the same night.

"All links must be very carefully examined. The suspicion seems likely that a certain date and the number of people to be expected were selected," he further told Bild.

At the same time, Maas warned people to not draw conclusions from the assaults regarding the general behaviour of law-abiding migrants. A police report said the suspects were mostly asylum seekers or people living in Germany illegally.

The number of complaints related to the mass assaults has rocketed to 379, more than double the previously reported number of around 170.

Around 1,000 intoxicated men are thought to have robbed, sexually harassed and in some cases raped women during turn-of-the-year celebrations.

The wave of New Year's Eve crimes in Cologne was mirrored in Hamburg, where 108 complaints were filed, and to a much lesser extent in other European cities.

Blame on refugees?

"To infer from someone's background that he is more likely to commit a crime or not I find to be risky," Maas said.

He also said it was totally wrong to make any connection between the excesses of New Year's Eve in Cologne and the arrival of over one million refugees in Germany in 2015.

"Of course, there are among the more than one million people those who commit crimes, but there is no indication that the number of crimes has risen disproportionately since the influx," he said.

What happened?

The attacks, as per victims' statements were carried out by men of North African and Arab appearance. It has also called into question Merkel's open-door migrant policy.

The police's handling of the events has also been sharply criticised. There were clashes at an anti-immigrant protest in Cologne.

Police used water cannons and pepper sprays to disperse protesters from the right-wing anti-immigrant Pegida movement as violence flared after a rally which heard condemnation of Merkel's policies.

Merkel talks tough:

Angela Merkel, speaking after a meeting of her Christian Democrat party leadership in Mainz, proposed tightening the law on denying the right of asylum for those who have committed crimes.

Under the new plans, those on probation could be deported from Germany.

"When crimes are committed, and people place themselves outside the law... there must be consequences," she told reporters after the meeting.

Under current German laws, asylum seekers are forcibly sent back if they have been sentenced to at least three years' imprisonment, and providing their lives are not at risk in their countries of origin.

The move, which will still need Parliamentary approval, follows the New Year's Eve attacks in Cologne, which sparked outrage in Germany.

A statement issued by Cologne police on Saturday, quoted by AFP news agency, said the number of reported violence cases had reached 379 - 40 per cent of which were cases of sexual assault.

"Those in focus of criminal police investigations are mostly people from North African countries. The majority of them are asylum-seekers and people who are in Germany illegally," the statement says.