BERLIN, Dec. 22 (UPI) -- The Berlin Christmas market where a suspected Islamist extremist killed at least 12 people reopened Thursday with the addition of concrete barriers to prevent a repeat attack.
The market's reopening in Berlin's Breitscheidplatz district on comes amid a large-scale manhunt for 24-year-old Tunisian suspect Anis Amri.
Police carried out raids in the city of Dortmund in western Germany but have not apprehend Amri, German prosecutors said. German news outlet Bild reported four suspects who were in contact with Amri were arrested but a prosecutor spokesman said he was not aware of any arrests.
Officials also carried out raids at a migrant center in Emmerich, where Amri briefly stayed in 2015, and at Berlin addresses.
Bild also reported Amri's fingerprints were found inside the truck used in the deadly attack, which also injured at least 49 people.
The Islamic State took credit for the attack on Tuesday, but authorities are skeptical of the claim -- due to similar statements by the group in previous attacks that police believe it had no real involvement with.
Amri communicated with the Islamic State at least once, was on a U.S. no-fly list and researched how to make explosives online, The New York Times reported.
Investigators said Amri has a criminal record and first emigrated from Tunisia in 2011, and spent three years in Italy. He is believed to be a supporter of the Islamic State, but likely not a true member.
Officials said Amri arrived in Germany in July 2015 and lived in multiple locations around the country for 17 months. He was refused asylum from the German government in June because he was facing deportation on suspicion of "preparing a serious act of violent subversion." He was, however, granted "toleration" status to remain in Germany legally.