What happened at Saman Restaurant in Kalk

I walked by Saman To Go near the Köln Arcaden in Kalk yesterday and there was about 15 police officers in and around the restaurant. I was curious if anyone knows what the hell was going on there? This was around 1pm and then I passed by again at 6pm and it looked like business as usual. At around the same time there were also a bunch of police officers at the Saman Restaurant near TH Köln.