Some students in Colombia got an unlikely surprise Wednesday when they experienced a burning sensation on their foreheads after being marked with ashes in an effort to acknowledge the beginning of the Catholic Church's Lenten season.

According to Fox News Latino, around 20 students from the Rio Negro, Medellin's Institución Educativa Gilberto Echeverri Mejía got rashes on their foreheads after receiving the ashes. They reportedly splashed water on themselves for relief and noticed they sustained burn marks.

Further, this incident isn't the first to happen in Colombia. Just last year, San Antonio de Pereira parishioners also sustained burns after getting marked with ashes on Ash Wednesday. The vicar, Andrés Felipe Vasquez, believed it must have been due to an allergic reaction and dismissed superstitious speculations about the incident.

A similar incident also happened in 2014 in Ireland, specifically Newtownshandrum in north Cork. About 30 parishioners also experienced burns on their foreheads on Ash Wednesday after receiving the traditional ash marking. Fr. Eugene Baker had to stop the mass to help the ones affected seek relief, advising them to wash the ashes off in the church's sacristy.

"It has never happened to me before. Has it happened to other people? I don't know," he said.

"It happened immediately. There was a tingling sensation really - those who came to me afterwards said it was a tingling sensation," he added. "They wiped it off immediately and they alerted me and I told people to go to the sacristy and wash it off."

Fr. Baker did not stop there - he sent the ashes for testing at a public health laboratory, Independent.ie reported.

Another such incident also occurred at another County Cork parish within the same year. Upon investigation, Westside Parish's Monsignor Malachy Hallinan said that the burning effect was most likely due to the fact that the leaves used to make the ash was too dry and became caustic after mixing it with water.

He noted that the ash was dry, clear, and white, and when added, it "fizzed a bit," the BBC quoted him as saying.

"I examined it and didn't find anything wrong, although I didn't put it on my own forehead, which I should have done," he noted.

"The material was strongly caustic - the reason for it was total combustion of organic material, where all the carbon material was burned away and all that remained was ash," he explained further. "Once this ash is mixed with water, the chemicals react to produce potassium hydroxide and similar caustic material."

He went on to recommend that the palm leaves burned for the Ash Wednesday rite should be green and fresh so it has a lower pH level when turned to ash.

WATCH: