Police in a Chicago suburb were investigating on Tuesday an act of vandalism at a Catholic church in which the heads were removed from statues of Mary and Joseph in a convent garden.

The destruction was discovered on Sunday, while parishioners at St Odilo in Berwyn, a largely Hispanic suburb of Chicago, were gathering to mark the upcoming feast on December 12 of Our Lady of Guadalupe, said Pastor Anthony Brankin.

Our Lady of Guadalupe, a depiction of the Virgin Mary, holds significance for Hispanic Catholics because of reported apparitions in Mexico in 1531.

Besides removing the heads, vandals also knocked over a statue of Jesus and egged a nativity scene in front of the church, Brankin said.

Brankin said he learned of the incident when someone screamed.

Vandalism of Nativity scenes in front of US churches are common around Christmastime. Sometimes statues of the infant Jesus are stolen from such displays.

"It was very intentional, I think, to do something against religion in a very religious week and a very religious month," Brankin said.

Berwyn Police confirmed their investigation, but had no comment.