A member of the ruling family of Ras al-Khaimah, one of seven states that make up the United Arab Emirates, has been held "without charge" for days, his son said on Wednesday.

Sheikh Sultan al-Qassimi, a first cousin of the emir who heads the local branch of the Islamist group al-Islah, was arrested on Friday by "armed men in civilian clothing," his son Sheikh Abdullah told Agence France Presse by telephone.

The United Arab Emirates warned on Monday that a Gulf islands dispute with Iran threatens "international security."

The UAE has summoned Iran's ambassador to Abu Dhabi to denounce a visit last week by President Mahmoud Ahmadinejad to one of the three disputed islands, the official state news agency said on Monday.

Tehran on Monday warned Arab states in the Gulf that things could become "very complicated" if they do not act cautiously over a simmering islands dispute between Iran and the United Arab Emirates.

Foreign Minister Ali Akbar Salehi made the declaration to Iran's ISNA news agency on the eve of talks in Doha between the Gulf Cooperation Council (GCC) states over three tiny islands in the Gulf and claimed by both Iran and the UAE.

The United Arab Emirates has summoned Iran's ambassador to Abu Dhabi to denounce a visit by President Mahmoud Ahmadinejad to a disputed island in the Gulf, the official state news agency said on Monday.

The UAE's minister of state for foreign affairs, Anwar Qarqash, "summoned the Iranian ambassador... and handed him a letter of protest, denouncing" Ahmadinejad's visit on Wednesday to Abu Moussa, WAM reported.

Iranian President Mahmoud Ahmadinejad's controversial trip to the disputed Abu Musa Island, which is controlled by Tehran but claimed by the UAE, was a purely "domestic issue," an Iranian official said.

"The president's trip to Abu Musa island is a domestic issue that took place in the framework of the president's provincial tours," deputy foreign minister in charge of Arab and African affairs Hossein Amir Abdolahian was quoted as saying.

The United Arab Emirates recalled its envoy to Tehran on Thursday, state news agency WAM reported, after having protested over a visit by Iranian President Mahmoud Ahmadinejad to a disputed island.

"The foreign ministry has recalled its ambassador to the Islamic Republic of Iran, Saif Mohammed Abid al-Zaabi, for consultations," it said.

The United Arab Emirates on Tuesday detained six Islamists whose citizenship had been revoked for alleged links to groups that fund terrorists, their lawyer said.

The six men "were summoned by the interior ministry and told that they have two weeks to get new nationality and legalize" their presence in the country, Mohammed al-Roken told Agence France Presse

A powerful sandstorm blowing over the Gulf has disrupted air traffic in Yemen, and closed schools and sent hundreds of people to hospital with respiratory problems in Saudi Arabia.

The Saudi ministry of education announced on Monday the closure of schools in the north, east and south-west of the desert kingdom, a day after similar measures were taken in the capital Riyadh, the official SPA news agency reported.

Russia's secret service has arrested two men in connection with a plot to assassinate Prime Minister Vladimir Putin after the March 4 presidential elections, Channel One state television said Monday.

The station showed two men who said they were acting on the orders of Chechen warlord Doku Umarov. They said they prepared the attack in the Ukrainian port city of Odessa and were planning to carry it out in Moscow.

The president of the United Arab Emirates has issued a decree granting citizenship to more than 1,000 children of Emirati women married to foreigners, the official WAM news agency reported on Sunday.

"President Sheikh Khalifa bin Zayed al-Nahayan has issued decrees granting citizenship to 1,117 children of UAE women married to foreigners who satisfied requirements for citizenship," WAM reported.