Officials in the Philippines are warning Catholics that a longstanding Easter tradition of crucifixion and self-flagellation could be bad for their health, the U.K.'s Telegraph reports.

Thousands in the Philippines will reenact the crucifixion of Jesus Christ this week, considered Holy Week by the Roman Catholic Church. The most pious will fly the skin off their backs and crucify themselves as penance for their sins.

In the Philippine’s San Fernando City, 23 people, including two women, have signed up to reenact the crucifixion. Four will use real nails, the Telegraph reports.

But government officials are warning that doing so is dangerous and can lead to serious infections. They are encouraging worshippers to get tetanus shots first and to be sure to use clean whips and nails for their reenactments.

Click here to see pictures and for more on this story from the Telegraph.