Gardaí are investigating a number of arson attacks on the site of the new national children's hospital in Dublin.

RTÉ understands that the incidents took place over a number of months last year and that there have been no arson attacks on the site since Christmas.

Minister for Health Stephen Donnelly condemned the arson attacks.

"You would really have to wonder what is going on with somebody that they would try and set fires in a children's hospital," Mr Donnelly said, describing the project as "one of the most important pieces of healthcare infrastructure that we are going to have in Ireland..."

Mr Donnelly said that he was aware that the main contractor on the project BAM had put additional security in place.

"The report I have is that thankfully no one has been harmed and no major damage has been done," Mr Donnelly said.

A spokesperson for the National Paediatric Hospital Development Board confirmed that "there have been a number of arson incidents on the site of the new children's hospital on a campus shared with St James's Hospital."

"In all cases, these incidents were immediately reported to An Garda Siochána by BAM (the main contractor on the project), and remain the subject of an ongoing Garda investigation," the spokesperson said.

In a statement BAM said that it was "not in a position to comment as this is an ongoing Garda investigation."

A statement from the Garda press office confirmed that "Gardaí are investigating a number of incidents of criminal damage by fire that have occurred at a building site in the Dublin 8 area in recent months."

The new national children's hospital project been fraught with controversy.

The approved capital budget for the project is €1.433bn, but the overall project budget, including the integration and transfer of the services, comes to €1.73bn.

This month, the Minster for Health reiterated that "there are a number of items not included" in the capital budget, including construction inflation and the impact of Covid19.