(BBC) — A suicide bomber has killed four people at a memorial service in Kandahar for the assassinated half-brother of Afghan President Hamid Karzai.

Officials say the bomber apparently hid explosives in his turban and detonated them near the entrance of the mosque.

President Karzai was not present at the memorial. Four of his other brothers were but escaped unharmed.

Ahmad Wali Karzai, a controversial but key figure in Nato’s battle against the Taliban, was killed by his bodyguard.

President Karzai flew into Kandahar for his brother’s funeral on Wednesday, but left the city before Thursday’s service.