STOCKHOLM (Reuters) - Swedish prosecutors said on Tuesday they had released a second suspect detained over possible involvement in a truck attack in Stockholm this month in which four people were killed.

They said the person, who was detained on Sunday and has not been identified, was no longer a suspect in the case.

As well as the four deaths, 15 people were injured on April 7 when a truck ran into pedestrians on a shopping street before crashing into a department store in the center of the capital.

The suspected driver, a failed asylum seeker from Uzbekistan, remains in custody.