Lisbon, Aug 24 (IANS): The twin sons of Iraqi Ambassador to Portugal Saad Mohammed Ridha were being questioned by the police after they allegedly beat up a Portuguese boy who went into coma for several days.

The Iraqi ambassador's sons, Haider and Ali Ridha, 17, said on Tuesday that they were cooperating with the Portuguese police without invoking diplomatic immunity, and they will not leave Portugal until the case is closed, Xinhua news agency reported.

"We respect all the police proceedings and even though we did not do it, we could have invoked diplomatic immunity and we would not have had to answer any questions or investigation," one of the ambassador's sons said.

Ruben Cavaco, 15, was assaulted on August 17 by Haider and Ali Ridha in Ponte de Sor, some 180 km northeast of Lisbon, and suffered multiple fractures.

He was transferred to the Hospital of Santa Maria in Lisbon and left the intensive care on Tuesday morning after several days in coma.

In a statement released on Monday, the Iraqi embassy in Lisbon said the ambassador's sons were acting in legitimate self-defence after being "severely beaten" and insulted by six people.

Portuguese Foreign Minister Augusto Santos Silva said the case was extremely serious and the diplomatic immunity for the two sons of the Iraqi ambassador could be lifted if it was necessary for justice to be done, with the cooperation of the Iraqi authorities.

The Iraqi ambassador has been summoned to Baghdad over the case and left for there on Tuesday.