Rebels have moved their command base from Turkey to "liberated areas" inside Syria, they announced on Saturday as regime troops and rebels battled for control of a corridor near the border.
"The Free Syrian Army command has moved into liberated areas of Syria following arrangements made with battalions and brigades to secure these zones," FSA chief Colonel Riyadh al-Asaad said in a video posted on the Internet.
The next step would be to "liberate" the capital Damascus, he added.
Nearly 80 percent of towns and villages on the Turkish border are outside government control, and President Bashar al-Assad's portraits have been removed from many public buildings, according to the Syrian Observatory for Human Rights.
"The transfer will allow the command centre to be closer to the fighters," General Mustafa al-Sheikh, head of the military council grouping rebel chiefs, told AFP, but declining to say where the new command would be located.
Rebel-held areas of Aleppo came under regime artillery fire on Saturday, with loud explosions heard across the northern city, an AFP correspondent reported.
At least 11 soldiers and five rebels were killed in clashes in the Orm and Kaf Jum areas of Aleppo province, near the Turkish border, the Observatory said.
"The state has no presence except for military and administrative posts" in the western region of the province in northern Syria, Observatory director Rami Abdel Rahman told AFP by telephone.
He said the regime was determined to prevent rebels linking up between western Aleppo and the neighbouring province of Idlib as this would form an extensive insurgent-held region on the border with Turkey, which supports the rebels.
In shelling of several rebel-held district of Aleppo city, five members of the same family, including children, were killed in Maysar, said Abdel Rahman, whose Britain-based monitoring group relies on a network of activists on the ground.
The Observatory said regime artillery also targeted the districts of Katergi, Shaar, Sakhur, Hanano, Arkub and Marjeh.
In the central city of Homs, where rebels remain entrenched in many areas, at least one soldier was killed near the Old City, while a civilian also died in Juret al-Shiyah district, the Observatory said.
Outside Homs, four soldiers were killed in an attack on their vehicle and a man was killed elsewhere in the province, it said, adding that three rebels died in clashes in the flashpoint town of Rastan.
Elsewhere, security forces raided the town of Hara in the southern province of Daraa and fighting broke out in the village of Dael.
National Coordination Committee for Democratic Change head Hassan Abdel Azim, meanwhile, told AFP that three members of his normally tolerated opposition group who went missing Thursday on the Damascus airport road were probably detained by Syrian intelligence.