Top U.S. commander in Afghanistan warns of attacks on U.S. troops

(CNN) — The top U-S commander in Afghanistan warns recent comments by Afghan President Hamid Karzai may trigger attacks on troops.

General Joseph Dunford issued the warning Wednesday in a personal e-mail to his top commanders.

He says increasing tensions with Karzai and the Afghan military could directly put troops in harms way.

Karzai has made what officials call several "inflammatory" statements recently, including accusing the U-S of collaborating with the Taliban.