KABUL (Reuters) – The U.S. military in Afghanistan on Monday expressed regret for a publicity campaign aimed at winning hearts and minds that ended up offending scores of Muslims.

U.S. troops on Friday dropped dozens of free footballs for soccer-mad Afghan children from helicopters in an area of southeastern Afghanistan, all marked with flags of various countries.

But the balls depicted the Saudi Arabian flag, which features the Islamic declaration of faith and includes the names of Allah and the prophet Mohammed.

The idea of kicking something bearing their names is considered deeply offensive to Muslims.

“This ball … carries a message with it which, like an atom bomb, can cause carnage and insecurity in all parts of Afghanistan,” a leading Afghan private daily, Cheragh, said on Monday.

Fawad Ahmad, a shopkeeper in Kabul, said: “Americans themselves create insecurity by ignoring religious sensitivity, it is against Islam.

A spokeswoman for the U.S. military in Afghanistan said the ball distribution was part of a “goodwill humanitarian aid mission … for the enjoyment of Afghan children.”

Captain Vanessa Bowman said the military had been unaware of the sensitivity of the issue.

“We do regret any disturbances caused,” she said.

In the past few years Afghans have staged sometimes-bloody protests against the desecration of copies of the Koran by U.S. soldiers at Guantanamo bay, the printing of cartoons featuring Mohammed in Western media and the spiriting-away of an Afghan Christian convert after intervention from Western rulers.

The latest gaffe coincides with rising anger over the deaths of more than 350 civilians this year by Western troops, mostly in southern and eastern areas where the Taliban are largely active.