The inclusion of two Muslims in a foot-washing ceremony by Pope Francis is one of several gestures of openness towards the Muslim world that could change perceptions of the Vatican, observers said.

The two teenagers -- a boy and a girl -- were among the 12 inmates at a youth prison in Rome taking part in the unprecedented version of a traditional Holy Thursday ritual as part of a series of pre-Easter papal ceremonies.

"It was a very important moment," said Mustafa Cenap Aydin, founder of the Istituto Tevere, an association for Christian-Muslim dialogue in Rome.

The Turkish Muslim met with the pope as one of dozens of representatives of world religions after the Argentine's momentous election earlier this month.

"After September 11, there has been a stereotype that excludes Muslims from public life. But the pope's was a gesture of openness that shows that exclusion is not Christian," he said, referring to the 2001 attacks on the United States.

The Vatican and the Muslim world have had difficult ties in recent years and Al-Azhar, Sunni Islam's highest seat of learning, broke off ties with Francis's predecessor Benedict XVI for what it regarded as controversial statements.

Benedict had strongly called for protection of Christian minorities after a January 2011 suicide bombing at a church in Egypt.

He had already sparked fury in the Muslim world in 2006 when he recounted an anecdote in which a Byzantine emperor described the Muslim Prophet Mohammed as a warmonger who spread evil.

Both Al-Azhar and the 57-member Organisation of Islamic Cooperation based in Saudi Arabia have signalled their hopes for better relations under Francis.

In meetings with religious leaders and foreign ambassadors following his inauguration, the pope also indicated an interest in closer ties.

"It is important to intensify dialogue among the various religions and I am thinking particularly of dialogue with Islam," he said.

Francis -- the first non-European pontiff in nearly 1,300 years -- said he wanted to "build bridges connecting all people".

Muslim commentators have also picked up on the fact that the pope chose to name himself after St Francis of Assisi -- a mediaeval Italian saint who met with the sultan of Egypt Al-Kamil in an apparent effort to end the Crusades.

"Francis is the name of dialogue in difficult situations," said Professor Adnane Mokrani, an Islamic theologian from Tunisia who teaches at the Vatican's prestigious Pontifical Gregorian University in Rome.

"There are major positive signs of openness," he said.

Mokrani said that Thursday's foot-washing ceremony was "very beautiful, a human gesture", adding: "Even as a Muslim I followed this Holy Thursday ritual because it represents the core of the Christian message".

Despite diplomatic efforts by the Vatican under Benedict, Mokrani said Muslim leaders have remained "a bit cold".

"Perhaps with this transition, things could change," he added.

But Cenap Aydin was more sceptical, saying that while there was a lot of "enthusiasm" and "interest" among Muslims in the new pope, this was not reflected "at an official level".

Vatican experts meanwhile played down the significance of Thursday's ceremony in relation to Islam, saying it was intended mainly to show that the Christian message was open to all.

"They could just as well have been young Buddhists or Sikhs. He washed their feet because they were isolated youngsters, he did not want to make any distinctions," said Marco Tosatti, who writes for La Stampa daily.

"It is not a given that all Muslims will appreciate the gestures since imams are careful of any attempt by Christians to attract Muslims to their religion."