At least six people were killed on Monday in a crackdown carried out by the Syrian regime of President Bashar al-Assad, hours after government websites were hacked by an opposition group, dpa reported.
"At least five people were killed in Hama ... when Syrian security forces entered the town of Hilfaya and started shooting randomly at the houses and buildings in the area," activists based in Lebanon said.
They added that tanks pounded the al Rastan area in the province of Homs killing one person and injuring at least five other people.
The Syrian state-news agency SANA said Syrian authorities had seized a car in Homs loaded with weapons - among them Israeli weapons - explosive devices and ammunition.
"The authorities found an Israeli-made machine gun, hand grenades, including Israeli grenades, and some explosive devices, two of which are set for radio controlled detonation," SANA quoted a military source as saying.
It added that sophisticated communication devices were also discovered.
SANA said the authorities also found stolen Syrian army military uniforms that had been used "by the gunmen to commit their crimes and accuse the army of doing them after filming them and sending the footage to the satellite channels."
The Syrian government has been blaming "armed gangs" financed by foreign and Arab countries for the uprising against the regime of al-Assad.
Earlier, activists told the German Press Agency dpa that Syrian army tanks were targeting their heavy fire on a main highway leading to Turkey.
They added that more than 50 tanks were positioned near the al-Rastan area and that communications in the town was cut.
Syrian troops massed around several villages and the Douma suburb of Damascus, while reinforcements had also been sent to Qusseir, a town on the border with Lebanon, they said.
The army has been strengthening its presence in Qusseir since Saturday after civilians attempted to flee into Lebanon. Some 5,000 Syrian refugees have fled since the uprising started.
An activist based in Damascus told dpa by phone that the regime was now deploying tanks and army personnel in towns and villages which border Turkey and Lebanon to prevent Syrian activists and civilians from fleeing the country.
Foreign journalists are barred from Syria, and activists are increasingly in fear of giving their names in case of reprisal from the regime - which activists say has so far killed an estimated 2,700 people during its crackdown on pro-democracy protesters.
Syria's actions have sparked an international outcry, including from neighbouring Turkey, once among Assad's main supporters.
Turkish Prime Minister Tayyip Erdogan told CNN in an interview broadcast on Sunday that al-Assad will "sooner or later" be ousted by his own people.
"You can never remain in power through cruelty. You can never stand before the will of the people," Erdogan said.
Also Monday, a new opposition group calling itself Anonymous Operation Syria said it had hacked the official websites of several state institutions.
The homepages were replaced by an interactive map of Syria showing data of those killed by the regime since March.
The targeted sites were based in the cities of Homs, Aleppo, Latakia, Damascus, Tartous, Deir Ezzor and Palmyra.
The hacked versions of the webpages included a link to a site advising activists on how to maintain anonymity on the internet in order to evade government tracking.