The shooting, which took place at the Risbergska School, an adult education centre in the city of Örebro, is the deadliest school attack in the country’s history.
According to police, the attack, which occurred around 200km east of Stockholm unfolded on Tuesday (local time) after a number of students had left following a national exam.
“We heard three bangs and loud screams. Now we’re sitting here waiting to be evacuated from the school,” he told Expressen newspaper.
A terrified parent also told Swedish media outlet SVT News his daughter saw blood over the floor as teachers rushed to help students flee to safety.
“We have been in touch by text message the whole time,” he said. “She arrived at the school five minutes before the whole thing and has been very scared.”
Details have also emerged of the text message a teacher sent to a loved one as the attacker began his killing spree.
“He wrote that there was shooting with automatic weapons at the school and that they had taken shelter in a room. Then he wrote that he loved me,” a person who knows the barricaded teacher told Swedish newspaper Aftonbladet.
According to SVT News, head teacher Mokhtar Bennis wrote a text message during the chaos: “I’m inside Risbregska and I’ve got difficulty talking.”
Another teacher on campus told SVT News she was barricaded in her study room for an hour, explaining that she heard “gunshots very close to our study” and described there were “probably 10 shots”.
She described hearing a few shots in quick succession before a brief pause and then another round of gunfire.
Teacher Maria Pegado described the moment someone threw open her classroom door and yelled for them to get out before witnessing victims being dragged out.
“I took all my 15 students out into the hallway and we started running,” she told Reuters.
“Then I heard two shots but we made it out. We were close to the school entrance.
“I saw people dragging injured out – first one, then another. I realised it was very serious.”
Footage on social media showed students huddled in fear under their desks as sirens rang out across the school. Words across the video read: “We haven’t received any information, been sitting here for an hour in Örebro”.
The gunman, who was not previously known to the police and currently has no suspected links to gangs or terrorism, is believed to be among those who died in the shooting, Örebro’s district police chief Roberto Eid Forest said.
“This is a terrible event. This is exceptional, a nightmare.
Sweden’s justice minister Gunnar Strömmer confirmed 10 people have been killed and many injured.
He said police attended the scene as soon as the alarm was sounded and the primary suspect is understood to be dead.
Speaking about the attack, he confirmed the suspect was not known to police, telling media: “We still don’t know why this happened. We don’t know what the motives could have been. We hope to have those answers. Police are working very hard to find that out.”
Strömmer said police do not believe at present that there is a risk of further attacks.