PRAGUE, Czech Republic (AP) – The Czech Republic came to a standstill at noon Saturday as people across the country observed a minute of silence for the victims of its worst mass killing that left 14 dead and questions about the shooter’s motive.

National flags on public buildings flew at half-staff and bells tolled at noon. President Petr Pavel and speakers of both houses of Parliament attended a Mass for the victims at St Vitus Cathedral in Prague, the country’s biggest, which was packed.

“We’re all still in a shock in our own ways,” Prague Archbishop Jan Graubner said. “We need to clearly condemn what happened but we also need to look into the future.”

“Nobody should be left alone in these tough moments,” Charles University rector Milena Kralickova said in her remarks toward the end of the Mass. The shooting occurred inside the university’s Faculty of Arts on Thursday. Twenty-five other people were wounded before the gunman killed himself.

Police and prosecutors said they have evidence the 24-year-old shooter also killed his father earlier in the day and a man and a baby in Prague last week.

Similar religious services were held in other cities and towns, while Christmas markets in a number of places were closed or reduced their programs amid boosted security measures.

A sea of candles was shining at an impromptu memorial for the victims in front of the university headquarters.

“It’s been a horrible experience for us all but it still can’t be compared with what the victims had to experience at the time of the attack and what their dear ones have to experience now,” said Milos Vystrcil, speaker of the Senate who came to light a candle.