DUBAI, United Arab Emirates (AP) — A prominent former soccer player in Iran who has expressed support for anti-government protests says his wife and daughter were prevented from leaving the country on Monday after their plane made an unannounced stopover en route to Dubai.

Ali Daei, who had his own passport briefly confiscated after returning to the country earlier this year, said his wife and daughter departed from the capital, Tehran, legally before the flight made an unannounced stop on Kish Island in the Persian Gulf, where they were questioned by authorities.

He said his daughter was released but the doors to the flight were closed by then. He said his family had planned to travel to Dubai and return next week.

The flight-tracking website Flightradar24 showed Mahan Air Flight W563 being diverted to Kish Island before traveling onward to Dubai a couple hours later.

There was no comment from the airline or Iranian authorities.

Daei is one of several Iranian celebrities who have come out in support of the protests ignited by the death of 22-year-old Mahsa Amini in September. The Kurdish woman died after being arrested by Iran's morality police in Tehran for allegedly violating the country's strict dress code.

The protests rapidly spread across the country and escalated into calls for the overthrow of the theocracy established after the 1979 revolution, making it one of the biggest challenges to clerical rule in over four decades.

At least 507 protesters have been killed and more than 18,500 people have been arrested, according to Human Rights Activists in Iran, a group that has closely monitored the unrest. Iranian authorities have not released figures for those killed or arrested.

Before his passport was confiscated, Daei, a top international goal scorer and former Iranian team captain, had urged the government on social media to “solve the problems of the Iranian people rather than using repression, violence and arrests.” He later said it was returned to him.

The leaderless protesters, rallying under the slogan “women, life, freedom,” say they are fed up after decades of social and political repression by a clerical establishment they view as corrupt and out of touch. Iranian authorities have blamed the unrest on foreign adversaries like the U.S. and Israel.

Iran's paramilitary Revolutionary Guard said in a statement Sunday that it had arrested seven individuals in the southeastern city of Kerman with a “direct link” to Britain who were involved in the protests. It said some members of the network had dual nationality, without elaborating.

Iran has arrested a number of Iranians with dual nationality in recent years and convicted them of state security offenses in closed-door trials. Rights groups say such detainees are denied due process and accuse Iran of using them as bargaining chips with the West, something Iranian officials deny.