Syrian security forces killed at least 20 people on Friday as they pursued a crackdown on pro-democracy protesters after activists called for a no-fly zone to protect civilians and soldiers deserting the army, a rights group said.
The Syrian Observatory for Human Rights said the fatalities were in the protest hubs of Hama, in the north, and Homs in the centre, and that security forces encircled mosques and made arrests before and after weekly Muslim prayers.
"Eight civilians were killed in various neighbourhoods of Hama, 11 others in the city of Homs and one civilian was killed in Qusayr, in the region of Homs," the Observatory said in a statement received by AFP in Nicosia.
Hama and Homs are at the front line of the anti-regime protests that have rocked Syria since mid-March, since when the UN estimates more than 3,000 people, mostly civilians, have been killed in the bloody repression.
The army has been carrying out operations in Qusayr for several weeks, amid fighting there between troops and suspected army deserters, activists say.
"Despite the siege, the proliferation of checkpoints and the encirclement of mosques, people staged a mass demonstration in Kafr Nabl," a town in Idlib, near the Turkish border, demanding the "imposition of a no-fly zone," the rights watchdog reported.
People in the northwestern town also marched "in support of besieged cities," said the Britain-based watchdog, adding that security forces also opened "heavy fire" and arrested five people.
That call was echoed in Homs, the focus of military raids in recent weeks, where demonstrators came out in "most of the city's neighbourhoods," the Observatory said.
Several protests rocked Homs as worshippers emerged from midday Muslim prayers. Around 20,000 people marched in the restive Deir Balaa neighbourhood calling for the fall of President Bashar al-Assad's autocratic regime, the Observatory said.
Meanwhile, activists said heavy gunfire and five explosions were heard in Qusayr, a restive town near the Lebanese border, where security forces sought to break up demonstrators streaming out of several mosques.
Clashes were also reported in Hama between suspected army defectors and members of the regular army and the security forces.
Troops also raided the northwestern town of Kafruma, arresting 13 people, including a woman and her 12-year-old son, the Observatory added.
In Maaret al-Numan, also in Idlib, the funeral of a soldier who defected and was shot dead on Thursday by security forces turned into a rally demanding the fall of Assad's regime, and demonstrators further east in Deir Ezzor also came under fire as they streamed out of mosques.
The latest bloodletting comes as activists called for nationwide protests on Friday to demand the imposition of a no-fly zone over Syria to protect civilians and to encourage soldiers to defect.
"We call on the international community to impose a no-fly zone so that the Syrian Free Army can function with greater freedom," said the Syrian Revolution 2011 on its Facebook page.
A defecting army officer who has taken refuge in Turkey, Colonel Riad al-Asaad, claimed in July to have established an opposition armed force called the "Syrian Free Army," but its strength and numbers are unknown.
A UN-mandated no-fly zone was imposed over Libya to protect civilians as fighting raged to oust the regime of ex-dictator Moamer Kadhafi.
On October 4, permanent UN Security Council members Russia and China vetoed a proposed resolution that would have threatened the Syrian leadership with "targeted measures" unless it halted the bloody repression.