A man (50) has been arrested in Portugal over the death of an Irish boy (5) and a Portugese boy (6) in a quad bike accident on Friday.

The man is believed to have been detained in the vicinity of the accident, but not at the scene itself, and faces charges of manslaughter and failure to provide assistance at the scene of an accident.

The accident happened on Friday evening in Viavai town, some 200km north of Lisbon. 

The Irish child who died is believed to have suffered severe head injuries. His brother (7) is in intensive care, receiving treatment for injuries he sustained during the same crash.

Carrie-Marie Bratley of The Portugal News spoke to Newstalk's Breakfast this morning:

It is understood none of the three children travelling on the quad bike were wearing helmets.