A bomb planted in a police station killed at least one policeman in Somalia's southern port city of Kismayu on Monday, and militant Islamist group al-Shabab claimed responsibility.
"A policeman died and several others were injured after a bomb blast. We are investigating the cause of the blast," Hassan Nur, a policeman, told Reuters by phone.
Al-Shabab said the toll was higher. "We planted a bomb inside a police station in Kismayu. We killed four policemen and
wounded 27 others," its military operations spokesman Abdiasis
Abu Musab said.
Al-Shabab lost control of Kismayu in 2012, depriving it of a key source of funds. It had ruled most of south-central Somalia until 2011, when it was driven out of the capital Mogadishu by African Union troops.
Despite the loss of territory, al-Shabab still carries out major gun and bomb attacks, and often claims casualty numbers that conflict with those given by government officials.