Police say suspect, who is among the dead, acted alone as they continue the work of identifying victims

The gun rampage that left 11 people dead in the Swedish city of Örebro was “a one-man operation”, police have said, as local media identified the shooter as a former student of the adult education centre he attacked.

As Sweden reeled from the deadliest mass shooting in its history, investigators were working on Wednesday to identify the people who were killed and injured after the attack at Campus Risbergska just after 12.30pm on Tuesday.

Henrik Landerholm left behind documents at a hotel, a phone at an embassy and a notebook after a radio interview

Sweden’s national security adviser has announced his resignation as police opened an investigation after he inadvertently left classified documents at a hotel, one of a series of mishaps that Swedish media have revealed in recent weeks.

Henrik Landerholm, whose appointment two years ago sparked debate due to his longstanding friendship with the prime minister, Ulf Kristersson, also left a notebook behind after an interview and left his phone at the Hungarian embassy, incidents particularly embarrassing given his sensitive national security role.