Doha, Qatar: Barcelona star Jordi Alba has become the latest Spanish footballer to enter the Gulf diplomatic crisis after he was shown signing a T-shirt of Qatar's leader on Wednesday.

A video of Alba autographing the image of Emir Sheikh Tamim bin Hamad Al-Thani, which has become the symbol of Qatari resistance during the month-long row between Doha and neighbouring countries, was posted on Twitter.

Alba, 28, was visiting the Aspire Academy while on a promotional visit to Doha with teammates Gerard Pique and Sergio Busquets.

The Barcelona trio were later mobbed by hundreds of delighted fans as they did a meet-and-greet at the Mall of Qatar, a shopping centre in the west of Doha, close to the Emir's palace.

Alba follows in the footsteps of legendary compatriots and World Cup winners Xavi Hernandez and Iker Casillas who have taken to social media to air their views on the blockade of Qatar.

In June Xavi, who now plays in Qatar for Al Sadd and is a World Cup 2022 ambassador, posted a video on Twitter calling for an end to the crisis.

"I would like to call for an end to the crisis in the Arab world and the end of the blockade against Qatar," he said.

Days later, goalkeeper Casillas also voiced his support on Twitter for Qatar.

Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed ties with Qatar, accusing Doha of supporting extremism.

They have also presented Qatar with a list of demands, including closing down broadcaster Al-Jazeera.

Doha rejects the charges of extremism and called the demands "unrealistic".

The Barcelona stars' trip was organised by the Academy and Mall of Qatar.