Fierce fighting has been reported in Syria's two biggest cities -- Damascus and Aleppo -- as government forces seek to regain control of rebel-held areas.
An opposition source said government forces on July 22 had succeeded in retaking the Mezze district of Damascus.
Also on July 22, intense fighting was reported in and around Syria's largest city, Aleppo, as forces opposed to the regime of Syrian President Bashar al-Assad made a concerted effort to take the town.
A video recording was released on social media showing what appeared to be a Syrian rebel fighter, who said that he and his comrades were "going to liberate Aleppo and after that will continue to Damascus to the presidential palace to get rid of the traitor there."
Fighting was reported close to the government's main intelligence base in the center of Aleppo.
Overnight, opposition forces defaced a stone statue of Assad's father, Hafez al-Assad, in the middle of the same town.
The British-based opposition Syrian Observatory for Human Rights group said on July 22 that the death toll from the uprising since March 2011 now exceeds 19,000 people
Meanwhile, rebels claimed on the same day that they have taken control of the Bab al-Salama border crossing with Turkey.
Amateur video distributed by the Syrian Observatory for Human Rights showed armed men carrying the flag of the Syrian uprising at the border crossing.
In the video, one of the purported fighters says: "We liberated the Bab al-Salama border crossing from Assad's gangs after we surrounded them. They withdrew after we dealt them heavy losses."
The video shows official signs indicating that it was recorded at the Bab al-Salama crossing.
Syria's Neighbors Increasingly Concerned
The AFP news agency also quotes an anonymous Turkish official confirming that rebel forces took control of the frontier post.
Reports say that of the three main crossings between Syria and Iraq, rebels have maintained control over the Albu Kamal border point since the evening of July 19, and they also briefly held the Yarabiyah crossing along the northern part of the frontier between the two countries.
All information coming from Syria is difficult to confirm as foreign media are not allowed into the country.
Syrian authorities and rebels often release contradictory information and the situation in the country is changing very rapidly.
Meanwhile, Syria's neighbors are observing the situation in the country with growing concern.
Israeli Defense Minister Ehud Barak said on July 22 that Israel will not allow chemical weapons from Syria to reach Hizballah militants in Lebanon.
Barak made the comments to reporters while visiting an army base near Tel Aviv.
He declined to comment on an earlier remark he made indicating that Israel might conduct a military operation on Syria territory to prevent such a weapons transfer.
Also on July 22, Israeli defense official Amos Gilad said Syria is protecting its chemical-weapons stocks "as best as they can," but also said Israel fears they could fall into the hands of Hizballah as the regime of Syrian President Bashar al-Assad comes under additional strain.
With reporting by AP, AFP, and Reuters