Ban Ki-moon on Syria: Too many lives have been lost
12 April 2012 Last updated at 15:31 BST
A tense ceasefire is in place in Syria, but both sides report violations.
Syrian state TV has said a roadside bomb in the city of Aleppo killed one army officer and wounded 24 people, all of them officers and cadets.
The opposition said three people have been killed in Idlib and Hama, and there was "no evidence" of a significant withdrawal by Syrian tanks and troops.
UN Secretary General Ban Ki-moon said the onus was on the Syrian government to match words with deeds.
He said this was "the time for a fundamental change of course".