A shooter killed at least 14 people and wounded 25 others at Charles University in Prague on Thursday, marking the deadliest mass shooting the Czech Republic has seen in decades.

Police cordoned off the area around the school building. The next update from authorities is expected on Friday morning.

The Czech Republic will also observe a day of mourning on Saturday for those killed in the Prague shooting, officials announced at a joint news conference on Thursday.

During the day of mourning, flags will be flown at half-staff, a minute of silence will be held nationwide, and bells across the country will toll for the victims of the attack, according to the Czech Prime Minister.