Four people were arrested during minor scuffles between gardaí and anti-war protestors, as former British prime minister Tony Blair arrived for a book-signing event in Dublin city centre.

A number of objects, including shoes, were thrown but missed Mr Blair as he entered Easons bookshop on O'Connell Street to sign copies of his recently published autobiography.

Four men in their 20s and 30s were arrested as activists clashed with gardaí at a security barrier outside the shop.

The men have been released and are due to appear in court on 30 September.

A group of over 300 people had gathered to protest at Mr Blair's role in the wars in Iraq and Afghanistan.

The groups represented included the Ireland-Palestine Solidarity Coalition, the 32-County Sovereignty Movement and the Workers' Party Dublin branch.

Dozens of gardaí were on duty in O'Connell Street since early this morning and sections of the main thoroughfare were cordoned-off to traffic.

Mr Blair left the shop at 12.30pm after signing copies of his book for over two hours.

The clashes that marked his arrival were not repeated as he departed.

However, protestors did shout abuse at hundreds of customers as they left the store with their newly-signed books.

All proceeds from the book, A Journey, will go to the Royal British Legion.

Eason said there has been an 'unprecedented demand' for Mr Blair's autobiography.

Managing Director Conor Whelan said: 'We have had a huge customer demand for Tony Blair's book.

'We hold these events in response to our customer demands and they turned out this morning in very large numbers to meet Mr Blair. We are delighted that today's event was so successful.'

Radical Islamists a 'major threat'

Speaking on last night's Late Late Show, Mr Blair said he believed radical Islamists still pose a major threat and they must be dealt with.

He said that Iran is now one of the biggest state sponsors of radical Islam.

It must be prevented from developing a nuclear weapon, even if that meant taking military action, he said.

Mr Blair defended the decision to invade Iraq in 2003, despite Saddam Hussein not possessing weapons of mass destruction.

He said he understood the view of those who opposed the war, but it was 'the right thing to do'.

Tony Blair appeared on The Late Late Show

Peace Process

Mr Blair revealed that the Northern Ireland peace process was one of the few moments in politics he felt really proud.

The Middle East peace envoy described watching former Northern Ireland First Minister Ian Paisley and Deputy First Minister Martin McGuinness sitting together publicly for the first time.

'It was just such a strange and extraordinary sight and one of the few times in politics I felt really proud actually,' Mr Blair said.

Mr Blair described former Taoiseach Bertie Ahern as a friend and repeated the assessment of him he used in the book as cunning.

He said: 'He became a good friend. He behaved with extraordinary skill towards this thing because it was difficult.

'Both of us in this sense had the same feeling about it - that it might be difficult but it was worth trying to do and worth trying for.'

Mr Blair added: 'Sometimes you've got to be smart to get around these problems. They require creativity, they require imagination and they require an ability to get where you need to get to.

'That's cunning in the best sense.

'It was really hard. You were having conversations with people - particularly when you sat down with the Sinn Féin people and the Unionists - these were people with a bitter and entrenched hatred. So there was quite a bit of cunning.'

Mr Blair revealed he grew to like Mr Paisley and said he felt he mellowed.

'As time went on we established a kind of relationship. I think in the end he wanted to do what was right for his people, and did,' Mr Blair said.

He described Sinn Féin President Gerry Adams as tough and clever.