Queen Elizabeth and a former Irish Republican Army commander offered each other the hand of peace Wednesday in a long-awaited encounter symbolizing Northern Ireland's progress in achieving reconciliation after decades of violence.

The monarch and Martin McGuinness met privately inside Belfast's riverside Lyric Theatre during a cross-community arts event featuring many of Northern Ireland's top musicians, poets and artists. Media were barred from seeing their first handshake, but the two shook hands again a half-hour later for a TV camera and two photographers.

Underlying the sensitivity of the occasion, no live footage or sound was permitted to be broadcast. Outside, flak-jacketed police shut down all roads surrounding the theatre and told residents to stay inside their homes.

The first soundless TV footage showed a serious-faced McGuinness walking, hands behind his back, behind the queen as she met poet Michael Longley and pianist Barry Douglas in front of newly painted portraits of them and other Belfast artists. Also in the group was McGuinness' Protestant colleague atop Northern Ireland's unity government, Peter Robinson; the head of state of the Republic of Ireland, President Michael D. Higgins; and the queen's husband, Prince Philip.

Then, more delayed footage showed McGuinness and Robinson standing first in line to shake the Queen's hand, then Philip's. McGuinness and Elizabeth exchanged smiles and brief pleasantries.

McGuinness said he told the Queen, in Gaelic, "Goodbye and godspeed," and translated the phrase for her. She didn't appear to say anything, just smiled and listened.

Decades of peacemaking

The event marked the latest, perhaps ultimate, moment in two decades of Northern Ireland peacemaking that have delivered a series of once-unthinkable moments of compromise.

Experts say McGuinness, 62, was the IRA's chief of staff when the outlawed group assassinated the Queen's cousin, Lord Louis Mountbatten, in 1979, one of the most high-profile victims of a four-decade conflict that has claimed 3,700 lives.

The IRA formally abandoned its campaign to force Northern Ireland out of the United Kingdom and disarmed in 2005. Two years later, McGuinness became the senior Catholic politician in a new unity government, the central objective of Northern Ireland's 1998 peace accord. His coalition with Robinson has governed Northern Ireland in co-operation with Britain in surprising harmony since.

McGuinness' Irish nationalist party, Sinn Fein, had refused all contact with British royals until Wednesday. Its leaders were heavily criticized last year for boycotting the Queen's first-ever state visit to the Republic of Ireland, a widely celebrated event that demonstrated overwhelming Irish desire for strong relations with Britain.

The Queen came to Belfast on Wednesday as part of U.K.-wide celebrations of her 60th year on the throne. She is scheduled later in the day to see the city's new Titanic exhibition and attend an open-air party involving more than 20,000 locals at Stormont, the hilltop base for Northern Ireland's power-sharing government.

IRA die-hards opposed to the group's 2005 decision to renounce violence and disarm sought to express their disapproval of the Queen's visit before she arrived.

Police said nine officers were injured, none seriously, during overnight rioting on the edge of Catholic west Belfast. They said a crowd of about 100 teens and young men bombarded police units with 21 petrol bombs and other makeshift weapons. No arrests were reported, though police cameras videotaped the masked, hooded attackers in hopes of identifying them later.

And in a separate confrontation Tuesday night, one Catholic man was hospitalized after rival Protestant and Catholic groups clashed on the hilltop overlooking Catholic west Belfast. The Protestants were trying to vandalize a massive political display erected by the Catholics featuring an Irish flag and a slogan rejecting the Queen.