Pope Francis has accepted the resignation of Polish bishop accused of covering up child sexual abuse by priests, the Vatican said on Saturday, the second such decision in as many months.

Andrzej Dziuba, the 73-year-old bishop of Lowicz, central Poland, resigned "at the request of the Holy See", said the apostolic nuncio representing the Vatican in Poland.

Polish media have reported allegations that Dziuba knew of at least two paedophile priests in his diocese.

Instead of launching an investigation, he had simply transferred them to different parishes.

The apostolic nuncio said the Vatican had identified "difficulties" in Dziuba's management of the diocese, "in particular negligence in handling sexual abuse cases committed by some clergy against minors".

Last month, the Holy See announced the resignation of Andrzej Dziega, a former archbishop of Szczecin, who is also embroiled in a sexual abuse cover-up scandal.

Poland, long considered a Catholic bastion, has in recent years seen the once-powerful Church shaken by cases of paedophilia attempts by high-ranking clergy to conceal them.

Pope Francis has made combatting sexual assault in the Church one of the main missions of his papacy and has insisted on a "zero-tolerance" policy following multiple wide-reaching scandals.