TEHRAN (Reuters) - Iran's morality police are cracking down on the sale of Barbie dolls to protect the public from what they see as pernicious western culture eroding Islamic values, shopkeepers said on Monday.

As the West imposes the toughest ever sanctions on Iran and tensions rise over its nuclear program, inside the country the Barbie ban is part of what the government calls a "soft war" against decadent cultural influences.

"About three weeks ago they (the morality police) came to our shop, asking us to remove all the Barbies," said a shopkeeper in a toy shop in northern Tehran.

Iran's religious rulers first declared Barbie, made by U.S. company Mattel Inc, un-Islamic in 1996, citing its "destructive cultural and social consequences." Despite the ban, the doll has until recently been openly on sale in Tehran shops.

The new order, issued around three weeks ago, forced shopkeepers to hide the leggy, busty blonde behind other toys as a way of meeting popular demand for the dolls while avoiding being closed down by the police.

A range of officially approved dolls launched in 2002 to counter demand for Barbie have not proven successful, merchants told Reuters.

The dolls named Sara, a female, and Dara, a male arrived in shops wearing a variety of traditional dress, with Sara fully respecting the rule that all women in Iran must obey in public, of covering their hair and wearing loose-fitting clothes.

"My daughter prefers Barbies. She says Sara and Dara are ugly and fat," said Farnaz, a 38-year-old mother, adding that she could not find Barbie cartoon DVDs as she was told they were also banned from public sale.

Pointing to a doll covered in black long veil, a 40-year-old Tehran toy shop manager said: "We still sell Barbies but secretly and put these in the window to make the police think we are just selling these kinds of dolls."

Iran has fought a running battle to purge pervasive western culture from the country since its Islamic revolution overthrew a western-backed king in 1979, enforcing Islamic dress codes, banning Western music and foreign satellite television.

As another swipe at the West, Iranians will soon be able to buy toy versions of the U.S. spy drone that it captured in December, Iranian media reported.

Models of the bat-wing RQ-170 Sentinel - which Iran's military displayed on TV after it was downed near the Afghan border - will be mass produced in a variety of colors, reports said.