Three people were arrested after protesters threw eggs and shoes at former British Prime Minister Tony Blair when he arrived to sign copies of his memoir at a bookshop in Dublin on Saturday, national broadcaster RTE said.
No injuries were reported and the missiles did not hit Blair.
Some of the 200 activists who had gathered outside Eason, a bookstore on Dublin's main thoroughfare O'Connell street, clashed with police over a security barrier.
Security at Blair's first signing of his autobiography had been tight due to opposition by critics of Blair's decision to join the war in Iraq and by an Irish nationalist group opposed to British control of Northern Ireland.
Britain hold a probe into much-condemned Iraq war over the unproved premise about presence of mass destruction weapons in Iraq that has been never found.
Readers were not allowed to take photos or ask Blair to write any personal messages in the copies of his self-penned volume "A Journey", which describes what he called the "nightmare" that unfolded after the invasion of Iraq.
On RTE's "Late Late Show" on Friday, Blair said he stood by his decision on Iraq, adding that the military option should also not be ruled out to prevent Iran from acquiring nuclear weapons.
Blair, who converted to Catholicism after quitting Downing Street and whose maternal grandparents were Protestant farmers in Ireland, played a central role in striking a peace deal in Northern Ireland in 1998.