UNITED NATIONS (AP) — Syrian tanks attacked a convoy carrying the head of the U.N. observer mission, Secretary-General Ban Ki-moon said Monday. He again told the government to halt its violent crackdown on those fighting to overthrow President Bashar Assad’s regime.

“Yesterday, the convoy of Lt. Gen. Babacar Gaye was attacked by armed tanks. Fortunately, there were no injuries,” Ban told reporters. He said a dozen armored vehicles used by the observers have been destroyed by blasts and shelling.