Protesters turned their backs on US Ambassador Kevin O'Malley and Taoiseach Enda Kenny (pictured) as US Civil War monument was unveiled.@EileenMagnier/Twitter

US ambassador Kevin O’Malley was heckled and jeered by up to 100 anti-American protesters at a commemoration of Irish heroes of the US Civil War in Ballymote, County Sligo at the weekend.

O’Malley and Irish leader Enda Kenny were unveiling a monument marking the 150th anniversary of the ending of the US Civil War. It was estimated locally that 250 attended.

When he arrived O'Malley was met by placards stating "US war machine out of Shannon" and "Where’s the monument for one million dead Iraqis?"

Many protesters turned their backs and sat on the ground during the US National anthem

Shannon was used as a transit point for US soldiers during the Iraq war.

Protesters shouted “warmongers”and “American troops out of Shannon” when O’Malley tried to speak at the commemoration in Sligo and turned their backs on the US Ambassador as he talked about the Irish heroes of the US Civil War the Irish Times reported.

Irish Prime Minister Enda Kenny was also heckled by other protesters complaining about water charges.

Throughout the commemoration speakers outlining the Irish contribution to the US Civil War were drowned out and calls of “traitors”were hurled.

Prime Minister Kenny stated that he was used to peaceful protest but that “you would expect in a place like this that respect would be shown for the national anthems and for visitors from the US especially for the ambassador, himself the son of Irish emigrants.”

The monument is a sculpture in bronze, of a soldier on horseback, and is dedicated to all the Irish who served and died in the US civil war.

Many of the locals who attended were upset at the protest and made it clear to the dignitaries.

There were angry scenes afterwards as protesters clashed with local police as many sat on the road and refused to leave.

The town is already home to Ireland’s national monument honoring the Fighting 69th and Brigadier General Michael Corcoran, who was from Carrowkeel, near the town of Ballymote.

The base of the Fighting 69th monument made of steel from the wreckage of the World Trade Center, which was donated by Michael Lynch Memorial Foundation. Michael Lynch was one of the 343 members of New York's Fire Department who died in the 9/11 attacks.

Former Minister of State John Perry, who represents Sligo and North-Leitrim, told the Sligo Champion newspaper, “I feel this is a fitting tribute to the countless thousands of Irish emigrants who fought and died on both sides of a tragic conflict."