Dubai: Heavy shelling by government forces on Saturday targeted schools scattered across rebel-held areas along the outskirts of Damascus, activists said, as state media reported that the schools were being used as barracks for insurgents.

“Dozens of schools were targeted by government forces since Friday night, in the areas of Tadamoon, Adamiyah Al Sham and Zabandani,” claimed activist Haytham Al Abdullah, who added that the troops’ shelling is aiming at destroying education and health facilities in rebel-held areas across Syria.

The state-run news agency Sana rejected the accusations and said schools in some areas near Damascus are being transformed into “barracks for terrorists to launch attacks and prepare car bombs to target the innocent Syrian people.”

Elsewhere, the Britain-based Syrian Observatory for Human Rights reported heavy fighting in the northern provinces, especially in Aleppo, where rebels staged a wide-scale attack on a army base at the outskirts of the city.

The observatory said the rebel attack has inflicted heavy casualties, but did not specify numbers.

In Lebanon, five Syrians who were plotting to bomb a Shiite religious ceremony were arrested overnight. According to the Lebanese National News Agency, the men were preparing an explosive device to disrupt an Ashura ceremony on Sunday, in the market town of Nabatiyah, 54 kilometres south of Beirut.

Syrian rebels have accused the Lebanese Shiite movement Hezbollah of supporting and helping the regime of President Bashar Al Assad since the outbreak of the uprising in 2011.

Meanwhile, Syria said plans by Turkey to site Patriot missiles along its border was “a new act of provocation”, while allies Iran and Russia warned that the move would complicate the situation and could spark a regional conflagration.

Nato chief Anders Fogh Rasmussen reacted by reassuring Moscow that any such deployment would be a “defensive only” measure.

Turkey turned to its Nato partners earlier this week to request the deployment of the surface-to-air Patriot missiles to protect its troubled border with Syria, which is engulfed in a war that has cost some 40,000 lives.

Syria’s foreign ministry accused Ankara of causing “tension and destruction”, with state television quoting an official as calling it a “a new act of provocation”.

“Syria holds [Turkish Prime Minister Recep Tayyip] Erdogan responsible for the militarisation of the situation at the border between Syria and Turkey and the increase of tension,” the unidentified official said.

In Moscow, Russian Foreign Minister Sergei Lavrov warned that any deployment of Patriots by Turkey may create a temptation to use the weapons and spark a “very serious armed conflict” involving Nato.

“I understand that no one has any intention to see Nato get sucked into the Syrian crisis,” Lavrov said. But “the more arms are being accumulated, the greater the risk that they will be used.”

Nato spokesman Carmen Romero later said Rasmussen had told Lavrov by telephone that such a deployment “would in no way support a no-fly zone or any offensive operations”.

“Such a deployment would augment Turkey’s air defence capabilities to defend the population and territory of Turkey,” Rasmussen told Lavrov.

But Iran’s foreign ministry accused Turkey of aggravating the situation.

“Not only does it not help resolve the situation in Syria but it will also aggravate and complicate the situation,” spokesman Ramin Mehmanparast said, quoted on state television.

“The insistence [of certain countries] to resolve the Syrian crisis through military means is the main cause of tensions and threats in the region,” he said.