UN observers` vehicles came under fire as they drove away from Haffa, but the source of the gunfire was not clear, the UN said.
More than 200 UN observers have been deployed in restive areas in Syria to monitor a ceasefire plan that has gone into effect on April 12.
The bomb went off just seconds after a convoy carrying the head of the UN observer mission passed by.
Day in Pics: 29th August
August 29, 2014
Famous Ganesh Pandals in Mumbai