About 10 people including the gunman have been killed at an adult education center in what Sweden’s prime minister called the country’s “worst mass shooting.”

Sweden is set to tighten its gun laws, including a ban on certain semiautomatic weapons, after a mass shooting that left 11 people dead.

Swedish police confirm around 10 people were killed at a school for adults on the outskirts of Stockholm. The gunman is believed to be among the dead.