Dhaka, Feb. 6 -- At least 10 people, including the gunman, were killed Tuesday at an adult education center in what Sweden's prime minister called the country's worst mass shooting.

But a final death toll, a conclusive number of wounded and a motive hadn't yet been determined hours later, reports AP.Prime Minister Ulf Kristersson gave a news conference in the aftermath of the tragedy, which happened on the outskirts of Orebro. The city is about 200 kilometers (125 miles) west of Stockholm.

The school, called Campus Risbergska, serves students over age 20, according to its website. Primary and upper secondary school courses are offered, as well as Swedish classes for immigrants, vocational training and programs for people with intellectu...