Voicing alarm over the high level of violence and bombings in Syria, UN Secretary General Ban Ki-moon has said that "established terrorist groups" are suspected in many deadly attacks in the country, where the overall situation remains "extremely serious".
Ban briefed the 15-nation UN Security Council about the over year-long crisis in Syria in his periodic report as mandated by a UNSC resolution.
Expressing concern over the increase in the number of bombings in Syria, particularly in the cities of Damascus, Hama, Aleppo, Idlib and Deir al-Zor, the UN chief said, "the sophistication and size of the bombs point to a high level of expertise, which may indicate the involvement of established terrorist groups."
While Ban did not name any specific terror organisation, he has previously said he believes al Qaeda was responsible for two suicide car bombs that killed at least 55 people in Syria this month.
The UN chief also expressed disappointment over the lack of progress in bringing peace to the troubled nation despite efforts by UN-Arab League envoy Kofi Annan to broker peace between the warring government and opposition forces.
"The overall situation in Syria remains extremely serious and there has been only small progress on some issues," Ban said.
"There is a continuing crisis on the ground, characterised by regular violence, deteriorating humanitarian conditions, human rights violations and continued political confrontation," he said in the report.
The UN Security Council is slated to discuss Ban's progress report on Wednesday when it would also hear from Annan about the situation in Syria.
Annan is expected to travel to Syria soon to discuss the lack of significant progress in implementing his six-point peace plan, which had called for an end to violence by all sides, withdrawal of troops and heavy weapons from cities, deployment of the monitoring force and dialogue between the government and opposition aimed at a Syrian-led "political transition."
Ban said the unarmed UN observer mission in Syria (UNSMIS) has said "significant parts of some cities appear to be under the de facto control of opposition elements."
"There is an overall atmosphere of tension, mistrust and fear," Ban said. "The overall level of violence in the country remains quite high."
"The Syrian army has not ceased the use of, or pulled back, their heavy weapons in many areas," he said. "On several occasions, UNSMIS has heard the sound, or seen evidence, of shelling in population centres."
Ban also urged countries not to arm either side with any kind of military aid.
"Those who may contemplate supporting any side with weapons, military training or other military assistance, must reconsider such options to enable a sustained cessation of violence," he said.
"The government reportedly continues to receive military equipment and ammunition from other countries, and there are also reports of weapons being sent to opposition forces," Ban said.
In the report, Ban also cited the Syrian government's continuing use of heavy weapons, reports of shelling and "a stepped-up security crackdown by the authorities that has led to massive violations of human rights by government forces and pro-government militias."