Swedish prosecutors have apprehended a second person suspected of involvement in last week's attack at a school in which a 17-year-old girl was killed and three people were injured by a man wielding a sword, they said on Wednesday. A 17-year-old girl was killed and three boys wounded in the attack, as investigators continue to examine the circumstances and possible motive. Key points and original sources are listed below.

• Swedish prosecutors have apprehended a second person suspected of involvement in last week's attack at a school in which a 17-year-old girl was killed and three people were injured by a man wielding a sword, they said on Wednesday.S1

• A 17-year-old girl was killed and three boys wounded in the attack, as investigators continue to examine the circumstances and possible motive.S2