At least six people were killed Friday by Syrian security forces in the restive province of Homs, according to opposition activists, dpa reported.
"The Syrian army is tightening its siege on Homs in preparation for launching an assault to crush dissent in the province," Omar Homsi, an activist, told dpa by phone from Homs.
"Since the early hours of Friday, the government troops have been shelling areas near Baba Amr neighbourhood in Homs to prevent people from joining (anti-government) protests," Homsi added.
According to him, Syrian troops were also reinforcing their positions near the border with Turkey and making house-to-house searches for suspected army defectors in the province of Idlib.
Meanwhile, the Syrian National Council umbrella opposition group said the regime of President Bashar al-Assad was using an attack on an oil pipeline in Homs - which the government blamed on "terrorists" - as a pretext to mount a bloody clampdown on the flashpoint province.
"The regime is preparing to commit a massacre to quell the revolution in Homs," the group said in a statement on Friday.
Homs, which has a population of about 1.6 million, has been the target of frequent crackdowns by the government forces since a pro-democracy uprising started mid-March.