Three Italian soldiers and one Romanian have been killed in a roadside bombing in Iraq. Two of the Italians died instantly, but a third died later in hospital. A fourth is said to be seriously injured. The explosion occurred on a road southwest of Nassiriya, where the Italian contingent in the country is based.The attack is the worst to be suffered by them in Iraq since 2003 when a suicide bomber killed 19. Italy has some 2,600 troops in the region, but plans to withdraw them by the end of this year. The deaths could aggravate tensions at home in Prime Minister Romano Prodi’s broad centre-left coalition, which narrowly won this month’s general election. The far-left wants an immediate pullout but others within the alliance favour a phased withdrawal.