Twenty-one priests in the US city of Philadelphia have been suspended after being named in an inquiry into claims of widespread child molestation.

The move follows the release last month of a grand jury report in which 37 priests were identified as suspects.

Cardinal Justin Rigali, archbishop of Philadelphia, said the 21 Roman Catholic priests had been placed on leave while their cases were reviewed

He said he was "truly sorry" for the harm done to the victims of abuse.

The two-year grand jury investigation resulted in charges being brought against four priests and a Catholic school teacher last month.

The grand jurors also found that a panel set up by the archdiocese to handle abuse claims following an earlier grand jury probe in 2005 had worked mostly to protect the church.

'Difficult weeks'

Three of the 37 priests named as suspects in the grand jury report were suspended in February, a week after its release.

Five more were already on leave, serving elsewhere or no longer in active ministry, the Philadelphia archdiocese said.

The remaining eight identified were not being suspended because "independent examination of these cases found no further investigation is warranted", the archdiocese added.

The names of the priests concerned have not been released.

"These have been difficult weeks since the release of the grand jury report," Cardinal Rigali said in a statement.

"Difficult most of all for the victims of sexual abuse but also for all Catholics and for everyone in our community."

Philadelphia District Attorney Seth Williams praised the archdiocese for taking some of the steps called for by the grand jury.

But Peter Isely, of the Survivors Network of those Abused by Priests, told the Associated Press news agency that Cardinal Rigali had put the interests of the church above those of children, and should have suspended the priests sooner.