DUBAI (AFP) - Sheikh Rashid bin Ahmed al-Mualla, ruler of the emirate of Umm al-Qaiwain, died on Friday, the official WAM news agency reported. The sheikh, who was in his seventies, had headed the small emirate " one of seven members of the United Arab Emirates " since 1981. The UAE began a week of official mourning, during which flags will fly at half-mast. Government departments are to close for three days, from Friday through Sunday, WAM said. The weekend in the UAE is Friday and Saturday. Sheikh Rashid died in hospital in London, WAM said. The ruler had been ill for several years and his son Crown Prince Sheikh Saud has been running the affairs of the emirate. He will become official ruler of the emirate.