High alert

At the time of the kidnapping, Italian state television said the couple's minibus had been found riddled with bullets, without citing its sources for the report.

Mauritanian officials have said they have arrested and are interrogating a Malian citizen who they think may be responsible for the kidnap.

Armed groups, some of them with links to al-Qaeda of the Islamic Maghreb, operate across the vast, remote desert zone, which includes eastern Mauritania, northern Mali and southern Algeria.

The Italians' kidnapping came nearly three weeks after three Spanish aid workers were seized in Mauritania.