UN leader Ban Ki-moon on Monday condemned the terrorist bomb attacks in two Syrian cities but said UN observers had brought some improvement in areas where they have been deployed

UN Secretary General Ban Ki-moon on Monday condemned the terrorist bomb attacks in two Syrian cities but said UN observers had brought some improvement in areas where they have been deployed.

The UN chief called on "all parties" in the Syria conflict to halt violence and work with the growing UN Supervision Mission in Syria, UN deputy spokesperson Eduardo del Buey said in a statement.

Ban "condemns" what he called "terrorist bomb attacks" in Idlib and Damascus on Monday, the spokesperson said.

"While noting improvements in areas where UN monitors are deployed, the secretary general remains gravely concerned by reports of continued violence, killing and abuses in Syria in recent days.”

"He calls for armed violence in all its forms by all parties to cease immediately and full cooperation of all parties with the work of UNSMIS as it expands its presence on the ground," the spokesperson said in a statement.

The UN monitors are scheduled to visit the western cities of Homs and Hama on Tuesday.

The latest UN schedule comes a day after at least 20 people were martyred and scores of others injured in two bomb attacks in Idlib.