The Saudi religious police launched a nationwide crackdown Thursday on stores selling items that are red or in any other way allude to the banned celebration of Valentine's Day, a Saudi official said.

Members of the feared religious police were inspecting shops for red roses, heart-shaped products or gifts wrapped in red, and ordering storeowners to get rid of them, the official said. He spoke on condition of anonymity because he was not authorized to talk to reporters.

Red-coloured or heart-shaped items are legal at other times of the year, but as Feb. 14 nears they become contraband in Saudi Arabia.

The kingdom bans celebration of Western holidays such as Valentine's Day, named after a Christian saint said to have been martyred by the Romans in the third century.

Most shops in Riyadh's upscale neighbourhoods have removed all red items from their shelves.

A statement by the religious police, informally known as the muttawa, was published in Saudi newspapers, warning shop owners against any violations.

"Those who don't comply will be punished," the statement said, without spelling out what measures would befall the offenders.

The Valentine's Day prohibition is in line with Saudi's strict Wahhabi school of Islam that the kingdom has followed for more than a century. The birthplace of Islam also bans several Muslim holidays except the two most important ones because it considers them "religious innovations" that Islam doesn't sanction.

Even birthdays and Mother's Day are frowned on by the religious establishment, although people almost never get punished for celebrating them.

Many Saudis, who still want to mark the popular Valentine's, do their shopping weeks before the holiday.

Each year, the religious police mobilize ahead of Feb. 14 and descend on gift and flower shops, confiscating all red items, including flowers.