Prices for black market roses are reported to be rising

The Saudi Gazette quoted shop workers as saying that officials had warned them to remove all red items including flowers and wrapping paper.

Black market prices for roses were already rising, the paper said.

Saudi authorities consider Valentine's Day, along with a host of other annual celebrations, as un-Islamic.

In addition to the prohibition on celebrating non-Islamic festivals, the authorities consider Valentine's Day as encouraging relations between men and women outside wedlock - punishable by law in the conservative kingdom.

The Saudi Gazette reported that some people placed orders with florists days or weeks before Valentine's Day in anticipation of the ban, which is a regular occurrence.

"Sometimes we deliver the bouquets in the middle of the night or early morning, to avoid suspicion," one florist said.

Others were planning to travel to the more religiously liberal neighbouring countries, Bahrain or the United Arab Emirates, to celebrate.

Saudi Arabian authorities impose a strict Islamic code that prevents men and women from mixing.