The ruler of Ras Al Khaimah, the fourth-largest emirate of the United Arab Emirates, died on Wednesday, the state's news agency said.

Sheikh Saqr Al Qasimi, believed to be in his late 90s, had ruled the northern emirate of Ras Al Khaimah for more than 60 years, dating back to before the UAE's inception in 1971. He had been in hospital for several months.   

His 54-year-old son and crown prince, Sheikh Saud, has been named as the new ruler, the state news agency Wam reported, and the Supreme Council, made up of the rulers of the UAE's seven emirates, offered him their "full support".

Analysts do not see Sheikh Saqr's death as posing any risk to the overall political stability of the UAE, even though Ras Al Khaimah (RAK) is considered the least stable emirate of the seven-member federation.   

Ras Al Khaimah, the closest emirate to Iran, effectively has been under the leadership of Saud since his older half brother, Sheikh Khalid, was deposed as crown prince in 2003 by decree.

Khalid has campaigned for several years to regain the leadership, but most analysts believe it is unlikely he will win power. Some believed his quest -- and his popularity in the emirate -- could complicate any transition.   

A source close to Sheikh Khalid told Reuters on Wednesday his palace in Ras Al Khaimah had been surrounded by military vehicles. An eyewitness said there was also an additional security presence around the residence of Sheikh Saud.

In a video posted on his website on Wednesday, Sheikh Khalid said he had a legal right to rule Ras Al-Khaimah.  

"In the coming days and weeks I will be meeting with my family and friends and members of the Supreme Council, rulers of the emirates, outlining my agenda for the first hundred days of my lawful leadership pursuing legal implementation of my father's vision for RAK," he said in the video.

In 2003, the federal government dispatched tanks to guard the palaces of the then newly appointed crown prince Saud, a day after Khalid was dethroned.   

Analysts said this time the succession process would most likely be smooth. 'I don't foresee any real problems, I think the issue has been settled. The authorities in Abu Dhabi and at a federation level will not allow any sign of friction or instability,' Emirati politics professor Abdulkhaleq Abdulla said.

Sheikh Khalid spent several years abroad before recently returning to the UAE, although he had stayed in the neighbouring emirate of Sharjah. He returned to his Ras Al Khaimah palace on Wednesday, the source close to him said.

Ras Al Khaimah, one of the poorer emirates of the UAE, sits on the Strait of Hormuz, through which 40 percent of the world's seaborne oil passes.   

The emirate's economy is based on industries like cement, pharmaceuticals, and glass, and building a regional manufacturing and shipping hub. Its gross domestic product accounts for 1.5 percent of the UAE's economy.   

The government announced an official mourning period of a week with flags at half mast and said it would close government ministries and institutions.   

The emirate has its own sovereign wealth fund, the Ras Al Khaimah Investment Authority (Rakia), which has a portfolio of around $2 billion. - Reuters