Robert Mugabe, Zimbabwe's president who is under a European Union travel ban, has arrived in Italy for the inauguration of Pope Francis.

Mugabe arrived in controversy after police in Zimbabwe on Sunday arrested four of Prime Minister Morgan Tsvangirai's aides and a prominent human rights lawyer following a referendum that would curtail the president's powers.

The 89-year-old Mugabe, who is a Roman Catholic, considered becoming a priest when he was young.

But he has in the past persecuted Catholic leaders, clerics from other churches and those who oppose his rule in Zimbabwe.

He has ruled  since 1980, when his country got independence from Britain, ingnoring past election results that have gone against him.

The Zimbabwe president can evade the EU travel ban if he enters Italy for religious reasons. The Vatican is not part of the European Union.

Mugabe visited the Vatican previously in 2011 to attend the beatification of late pope John Paul II.

In 2005, when Britain's Prince Charles found himself seated near Mugabe at the funeral of John Paul at one point shook his hand.

The office of the prince later the heir to the British monarch was caught by surprise after Mugabe offered his hand to the man representing British royalty from the former colonizer of his country.

Vatican spokesman, Rev. Federico Lombardi, explained last week that the Holy See does not formally invite diplomatic missions to attend the papal Inauguration Mass. It rather informs countries through diplomatic channels that the event is taking place.

Mugabe is unlikely to get a handshake from Ugandan-born John Sentamu, the (Anglican) Archbishop of York who will be there without his clerical collar, often called a dog collar.

Senatumu who will be representing the Archbishop of Canterbury, Justin Welby, has pledged he will not wear his clerical collar until Mugabe is out of office.

"The Archbishop will stick to his principles. He cut up his dog collar on the [BBC's] Andrew Marr Show on 9 December 2007 and said that he would not put it on again until Mugabe was out of power. He has no intention of putting it on again until that happens," one of his aides said in 2011.

Sentamu, 63, caused a stir among Anglicans when he cut up his symbol of being a clergyman, asking his interviewer: "Do you know what Mugabe has done? He has taken people's identity and literally cut it to pieces.

"So, as far as I'm concerned, from now on I'm not going to wear a dog collar until Mugabe is gone."