DUBAI (Reuters) - Five Emirati humanitarian workers were killed in a bomb attack in the southern Afghan city of Kandahar, the United Arab Emirates (UAE) official news agency reported on Wednesday.

The five were killed on Tuesday while engaged in humanitarian, educational and development work, state news agency WAM reported, adding President Sheikh Khalifa bin Zayed al-Nahyan had ordered flags flown at half mast for three days in mourning.

Afghan officials said the explosion killed at least seven people and wounded 18 others, including the UAE ambassador to Afghanistan.