Three people have been injured after a man attacked a mosque in the Swiss city of Zurich and opened fire on worshipers on Monday evening.

Police said the attacker stormed the Islamic Center on Zurich’s Eisgasse Street and fired several shots at a group of people who had gathered there for prayers. The shooting left two of the three men seriously wounded.

Officials did not comment on the possible motive, as they were still gathering evidence inside the building late in the night.

“The three men who have been shot are in the hospital. We couldn’t question them yet. We are also looking for eyewitnesses who were in the area during that time. And the forensics are ongoing as well,” said Zurich police spokesman Marco Bisa.

The unidentified suspect fled the mosque and police were searching for the attacker, a man about 30 years old, who according to witnesses was wearing dark clothing and a dark wool cap.

Police noted that a body was found near the scene of the shooting but would not comment on whether it might have any link to the attack. Authorities are scheduled to give further details on Tuesday.

People at the scene said the center was used as a mosque that attracted worshipers, often Somalis.

Abukar Abshirow, a Somali man who often performs prayers at the mosque, said he knew the three victims, adding they were Somalis.

“I am shocked … This mosque has been here since 2012 and we have never had any problems. We never had to deal with the police, we never had arguments. This was a quiet, joyful place,” he said.

Muslims make up about five percent of Switzerland’s 8.3 million population. Anti-Islam sentiments have been rising particularly with the arrival of refugees from conflict zones in the Middle East and elsewhere.