Pickpockets Target Royston Church
Police are investigating a number of thefts from a church in Royston.
The thieves have stolen mobile phones, wallets and a young girl's bag at Royston Methodist Church over the last four months.
Hertfordshire Police are now warning church-goers to be on their guard.
A cash collection box and a silver goblet have also gone missing during recent services.
Reverend Chris White said: "To steal from someone who has come to church to pray is terrible.
It could be anyone who was at the services."
Church officials have been advised to install CCTV to combat the thefts.
However, Reverend White is not keen to beef up security in this way.
Reverend White added: "We don't want to put CCTV into the church and make it like a fortress.
It should be a welcoming place, just not for thieves."
Sergeant Jon Vine, from Hertfordshire Police, said: "While these sorts of incidents are rare in North Herts, we would always advise people to remain vigilant at all times and follow common sense advice."
One person had been arrested in connection with an allegation of theft, but was released without charge.