Tens of thousands of people have attended a Mass celebrated by Pope Francis in the Cuban capital Havana on his first visit to the Communist-ruled island.

Cuba’s President Raul Castro, not a practicing Catholic, attended the event Havana’s iconic Revolution Square.

Later Pope Francis also met the president’s brother and predecessor, Fidel Castro.

Pope Francis, who is at the start of his Cuba and US trip, has been credited with helping the recent thaw in diplomatic ties between both countries.

Photo Reuters

After his arrival on September 19, the pontiff hailed improving ties between Cuba and the US as “an example of reconciliation for the whole world”.

Pope Francis also urged both Cuba and the US to “persevere on the path” of detente.

Security services were seen arresting at least three people who were shouting and attempting to distribute flyers at the edge of Revolution Square as the Mass got under way.

On his way to the service Pope Francis stopped to greet some of the thousands who had come out to see him.

During his homily the Pope said that “Christians are constantly called to set aside their own wishes and desires, their pursuit of power, and to look instead to those who are most vulnerable”.

After the Mass, Pope Francis met Fidel Castro at his house in Havana for about 30 minutes.

According to the Vatican, Pope Francis and Fidel Castro exchanged books as gifts.