A 20-year-old woman divorcee accused of committing adultery in Somalia has been stoned to death by Islamists in front of a crowd of about 200 people.

A judge working for the militant group al-Shabab said she had had an affair with an unmarried 29-year-old man.

He said she gave birth to a still-born baby and was found guilty of adultery. Her boyfriend was given 100 lashes.