As the fallout from a spree of sexual assaults against women alleged to have been carried out by groups of Middle Eastern men spreads, German authorities are scrambling to come up with measures to beef up security and punish migrants convicted of serious offenses.

The events in Cologne on New Year's Eve, in which groups of "North African and Arab" men reportedly robbed and sexually assaulted at least 120 women, are something that should never happen again, Interior Minister Thomas de Maiziere told German regional daily "Rheinische Post" on Friday.

Ahead of a high-level meeting of Chancellor Angela Merkel's Christian Democratic Union (CDU) party officials on Friday, de Maiziere said authorities would focus on "prevention, more video surveillance in public places where many people gather, police presence on the streets and tougher penalties" to avoid a repeat of the mass sexual assaults.

The Cologne events are rapidly turning into a political crisis for the CDU and its open refugee policy: 1.1 million refugees - nearly 75 percent of whom are from Syria, Iraq and Afghanistan - arrived last year.

Based on the first internal report by the Cologne police, multiple media outlets have suggested a significant number of suspects were asylum seekers.

Quoting police sources, Cologne daily "Kölner Stadt-Anzeiger" said the officer leading the team at the station wanted the report to include mention of Syrians and asylum seekers, but the senior officer writing the police report decided not to, saying it would be "politically awkward."

As the investigation into sexual assaults in Cologne progresses, politicians are already trying to get out in front of any public backlash against any new asylum seekers who may break the law.

De Maiziere said asylum seekers who commit serious crimes such as sexual assault could even be expelled from Germany. According to an outline government proposal seen by Reuters ahead of the CDU conference, asylum seekers and refugees could be put on probation or expelled.

The document calls for hurdles to deport and remove convicted foreigners to be lowered.

However, the general secretary of the CDU, Peter Tauber, questioned on Friday whether the justice system had already exhausted all of its options.

"For violent crime we already have strict enough legislation," Tauber told German public radio, noting that the issue comes down to the courts applying the law.

Vice Chancellor Sigmar Gabriel, the head of the Social Democrats (SPD), the CDU's coalition partner, echoed calls to strengthen deportation procedures for criminals.

"Why should German taxpayers pay to have foreign criminals jailed," Gabriel said. "The threat of having to spend time behind bars in their home country is far more of a deterrent than a prison sentence in Germany."

The process of deporting refugees might be complicated given the legal repercussions of expelling someone to a war-torn country such as Syria, where they could face death.

cw/ng (dpa, Reuters)