Sweden’s right-wing government said on Friday it would seek to tighten gun laws in the wake of the country’s deadliest mass shooting at an adult education center where the attacker appeared to have used several of his own licensed rifles.

Swedish police said Sunday they were still struggling to establish the motive of the man behind the Scandinavian country’s worst mass shooting, five days after the tragedy. A gunman killed 10 people on Tuesday after entering the Campus Risbergska,

Five people have been shot at a school in Sweden as authorities warned the danger was not over while armed officers rushed to the scene. Armed police descended on the Risbergska School, an adult educational institute in the city of Örebro some 200 km (125 miles) west of Stockholm on Tuesday.