Rome/Berlin - Investigators in Italy and Germany were worried Thursday about the whereabouts of a German couple who had abandoned three children at a pizza restaurant in northern Italy.

Police continued their search for the 26-year-old mother and her 24-year-old male companion, who have not been seen since telling the children Sunday that they were going outside to smoke a cigarette.

Investigators fear the couple may think they are "in a desperate situation and it could therefore come to an act out of panic," a document issued Thursday by German state prosecutors said.

Two boys, ages 10 months and six years, and their 4-year-old sister are being cared for by a foster family in the town of Aosta. German officials are due to take them home Friday.

"So far the children are doing well, as far as we know," said a town spokesman in the family's home town of Olpe, 70 kilometres east of Cologne.

Upon their return, the children are expected to stay initially with their grandparents.

The man accompanying the mother-of-three had escaped three weeks ago from a German prison. Investigators have given the man the chance to return of his own free will. (dpa)