Image caption Cardinal Bertone is the Vatican's number two

The Vatican has stepped up its criticism of raids by Belgian police investigating alleged child sex abuse, calling the detention of priests "serious and unbelievable".

Cardinal Tarcisio Bertone, the Vatican Secretary of State, said "there are no precedents, not even under the old communist regimes".

He claimed the priests were held for nine hours without eating or drinking.

Several buildings of the Belgium Church were searched on Thursday.

Bishops holding a meeting there were barred from leaving the premises for several hours.

"It was sequestration, a serious and unbelievable act," said Cardinal Bertone.

'Astonishment'

Police in Leuven seized nearly 500 files and a computer from the offices of a Church commission investigating allegations of sex abuse.

They also searched the Church's headquarters, the Brussels archdiocese in Mechelen, north of the Belgian capital.

Prosecutors have said the raids were over alleged "abuse of minors committed by a certain number of Church figures".

On Friday, the Vatican voiced "astonishment" at how the raids have been carried out, saying police had drilled holes in two archbishops' tombs.

The Vatican said the raids had led to the "violation of confidentiality of precisely those victims for whom the raids were carried out".

The Vatican has summoned the Belgian ambassador to the Holy See to voice their anger at the incident.

The Catholic Church in Belgium has apologised for its silence on abuse cases in the past.