BERLIN — In Germany, break-ins are on the rise and it seems not even churches are safe. In 2015, police registered 167,000 domestic break-ins — a 10% increase on the previous year.

But thieves who target churches constitute a particular breed.

"The most organised are thieves who are hired by collectors to steal," says insurance expert Lutz Dettmer of the Ecclesia Insurance agency. "These clients have usually cast their eyes on art treasures or sacred objects."

Unless the objects are sold soon after they have been stolen, it can be quite difficult to trace and retrieve them.

One such case occurred three years ago in the bishopric of Münster, where thieves stole the Borghorst monastery crucifix, a significant gold item dating back to the 11th century. The three perpetrators were eventually caught and sentenced to a few years in prison, but the crucifix has never been found.

For church communities, these items are often irreplaceable.

"The material value of these items may be low but the loss of their intrinsic value is much larger," said dean of the Cologne Cathedral, Gerd Bachner in the summer during which thieves stole a reliquary containing the blood of Pope John Paul II.

Many of the thieves are merely petty criminals, stealing church valuables without rhyme or reason. Others are trying to finance their drug addiction.

They break into church community centers and church-run kindergartens because the loot from these institutions can often be sold on much more easily than art treasures. But generally speaking they steal "everything that isn't tied down," according to the diocese of Rottenburg-Stuttgart.

Dettmer recalls a case in Düsseldorf, where thieves stole an intricately and richly decorated monstrance from a church and tried to sell it at a nearby pawn shop. Employees there alerted the police who later arrested the thieves.

Beyond the more sacred items like monstrances and chalices, thieves regularly break open the offertory box, which contains monetary donations made to the church. Microphones and other technological items are up for grabs, as are metal objects like copper spouts.

Catholic communities are typically targeted because their churches tend to be furnished with highly valuable materials.

But more often than not, the biggest financial cost comes not from the loss of these items but rather the damage caused to windows and doors during a break-in.

Crime statistics also show that there are regional differences in the rates of theft, with more churches in the country's east and north targeted than in the south and west.

"It appears to be the case that in regions where the Church is still a part of community life the moral threshold to rob seems to be much higher," says Dettmer.

At the Lutheran Protestant Church in Saxony there were seven break-ins in seven days during the month of June. Whereas the bishopric of Augsburg in the southern region of Bavaria, which has more than 2,000 churches within its confines, registered only 42 break-ins, or attempted break-ins, in the last five years.

Aware they are facing a new challenge, churches have decided to take action incorporating theft prevention when planning refurbishments and new buildings.

At the archbishopric of Freiburg, a data bank contains 200,000 entries, including photos, pertaining to the church's art treasures. The Protestant Church of Central Germany has chosen to take a similar path.

"The awareness of the problem at hand is most certainly present," says Dettmer.

On occasion, police have managed to crack some difficult cases. A figurine of Saint John from the late Gothic period, which was stolen from a church in Haigerloch-Owingen (Baden-Wurttemberg) over 41 years ago, was recently discovered on sale on eBay. It led police to Slovakia where they reclaimed the item. It is likely to be returned to its traditional resting place soon.