Egypt's EgyptAir and UAE's Dubai- based Emirates Airlines have cancelled their flights to the Syrian capital of Damascus on Friday due to security concerns.

"Emirates has, with immediate effect, suspended its daily EK913 and EK914 services to/from Damascus until further notice," Emirates Airlines said on its website, without elaborating reasons.

The Dubai-based carrier, however, added in the statement that " the safety of our passengers and crew is of the highest priority and will not be compromised," prompting speculations that security situation around Damascus airport may be deteriorating.

A spokesperson of EgyptAir also told media that the carrier has cancelled its flights to Damascus on Friday.

On Thursday, Syrian government troops and opposition forces engaged in clashes near Damascus, cutting off the road to Damascus airport. Also on Thursday afternoon, most Internet and cell phone services in Syria were cut off.

"In the global routing table, all 84 of Syria's IP address blocks have become unreachable, effectively removing the country from the Internet," U.S. company Renesys, which was monitoring Syria's web traffic, said on its website.

According to Syrian activists, Syrian government often cuts Internet and phone services before launching major military operations, which on Thursday prompted speculations of imminent offensives by government troops.

Earlier on Thursday, an explosive device went off near the house of a leading member of Syria's ruling al-Baath party in the southern province of Daraa, killing three policemen and injuring others. The explosive device, weighing 50 kg, went off in front of the house of a secretary of al-Baath party in Daraa, causing damage to nearby buildings.

On Wednesday, a car bomb rattled the Busra town on the countryside of Daraa and killed two people.

Recently, the fighting has intensified between government troops and Western-backed rebels who are trying to erode Syrian government's grip on the capital and elsewhere in Syria in the hope of hastening the collapse of the Syrian administration.