Government troops have reportedly clashed with rebels in the Syrian border town Nasib, near Jordan (AP)
The leaders of the rebel Free Syrian Army have said they have moved their command centre from Turkey to Syria.
Brigadier General Mustafa al-Sheikh, who heads the FSA's Military Council, said the move aims to unite all rebel groups.
He said the move was made the week before, without specifying the FSA's new location.
Commander Colonel Riad al-Asaad issued a video titled "Free Syrian Army Communique Number 1 from Inside" revealing that the command has moved to "liberated areas".
The FSA has been the most prominent of the rebel groups trying to remove President Bashar Assad from power.
But its commanders have come under criticism in the past for leading from Turkey, and its authority over numerous locally-based networks of fighters is limited.
Earlier, Syrian activists said rebels and government troops had fought a fierce battle near the border with Jordan. The activists said the fighting in and around the Syrian border town of Nasib continued until dawn on Saturday.
The Britain-based Syrian Observatory for Human Rights said there were casualties on both sides without giving figures. Mohammed Abu Houran, an activist in the area, said the rebels first attacked an air defence base near Nassib and as they were withdrawing they clashed with Syrian border guards.
Nasib is in the southern province of Daraa, where the uprising against President Bashar Assad's regime began in March last year.
The uprising later turned into a civil war that has claimed the lives of nearly 30,000 people, activists say.