The Taliban's reclusive leader said in a Muslim holiday message on Friday that his fighters must protect Afghan civilians, who are dying in rising numbers, so the insurgency can maintain good relations with the population.

Mullah Mohammad Omar posted his message on the Taliban's website ahead of next week's Eid al-Adha, or Feast of Sacrifice, when Muslims around the world slaughter sheep and cattle in remembrance of Abraham's near-sacrifice of his son.

In a midyear report, the U.N. said 1,462 Afghan civilians were killed in the crossfire between Taliban insurgents and Afghan, U.S. and NATO forces during the first half of this year _ up 15 percent from the same period a year earlier.

The U.N. report attributed 80 percent of the civilian deaths to insurgents and others fighting against the Afghan government. International troops and other pro-government forces were to blame for 14 percent of the deaths; 6 percent were not attributed to any side.

Omar said civilian casualties must be extensively investigated.

"If it is irrefutably proven that the blood of innocent Muslims is spilled by the negligence of mujahedeen, then a penalty should be implemented in accordance with Shariah (Islamic law) ... and all steps should be taken to seek the pardon" of those affected by the killings, he said.

Omar said civilians also need to take steps to keep themselves safe.

"The common folk ... should avoid moving in close proximity to Americans that patrol in villages and countryside" because they are being targeted by the insurgents, he said.

The message, which the Taliban posted in English and other languages, was reported by the U.S.-based SITE Intel Group, which tracks militant websites.

The Taliban leader also claimed his fighters were winning the war and that support for the conflict among the U.S. public was waning.

The U.S.-led coalition has a different view.

Late last month, the coalition released statistics showing that since May of this year, the monthly number of enemy attacks has been lower than in 2010 _ something not seen since 2007.

The coalition said the Taliban were relying more on roadside bombs to fight the war instead of shooting at better-armed international troops. Roadside bomb activity, which includes both explosions and attempted bombings, rose 25 percent in the first eight months of the year compared with last year, the coalition said.