Almost 60 vehicles have been broken into at churches and cemeteries in County Donegal since the start of the year, the Irish police have said.
Cars are being broken into outside graveyards
Gardai believe one gang is responsible for most of the break-ins and think they are based in Northern Ireland.
The latest incidents took place at the weekend when two cars were broken into at different graveyards in Letterkenny.
A man and woman were seen in the area at the time driving a Northern Ireland registered car.
Detective Sergeant Michael Donaghue of the Garda said that while the crimes are likely to be opportunistic there is also the possibility they could be planned.
"It more than likely is opportunistic but the possibility they're listening to death messages on the radio - we couldn't rule that out," he said.
"There have been 57 similar type crimes in the division since the beginning of the year.
"We believe that the gang responsible for it are presently based in Northern Ireland. We believe they are responsible for most of the crimes."
Seamus O'Donnell's van was broken into at Cornwall cemetery in Letterkenny while he was visiting his parents' grave - just two days after his mother was buried.
Personal belongings, including his phone, were stolen. The phone contained text messages of support from friends following his mother's death.
His niece's car was also broken into after another family bereavement.
"You come to pay your respects at a graveyard, you're not thinking about the security of your car. You think that nobody's going to break into your car at a graveyard," Mr O'Donnell said.
"They have to be scum to break into cars at graveyards. It's a total lack of respect for people saying prayers at graveyards."
The mayor of Letterkenny, Ciaran Brogan, who is a friend of Mr O'Donnell, said people in the town were angry about the incidents.
"It's very disturbing for us in Letterkenny and we want to send out a strong message that we'll not tolerate this sort of behaviour.
"We've a very good community here, a good community spirit in Letterkenny."
A description of two people seen in the area of the latest incident has been issued by police.
The man was in his late 20s, tall and slim with fair hair. The woman was a similar age and "slightly plump". They were in a small blue car.