Dubai announced a three day mourning period after the 33-year old son of the Gulf emirate's ruler passed away, the official state news agency WAM said on Saturday.

Sheikh Rashid, son of the Prime Minister and Vice President of the United Arab Emirates Sheikh Mohammed bin Rashid al-Maktoum, suffered a heart attack on Saturday morning, the agency said.

Sheikh Rashid was the eldest son of Sheikh Mohammed. Rashid's brother Sheikh Hamdan is the Crown Prince of Dubai.