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.”

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.

Eleven people were killed in a shooting at an adult education centre on Tuesday, Swedish police said, marking the country's deadliest gun attack in what the prime minister called a "painful day."