The Syrian army met armed resistance in two towns on Thursday, with activists reporting 19 killed in clashes, as the EU decided on a new set of sanctions on President Bashar al-Assad's regime.
The Syrian Observatory for Human Rights, updating an earlier toll, said 10 people were killed in Banash town in Idlib province in the northwest .
"The Syrian army backed by tanks and armoured troop carriers launched an assault this morning on the town of Banash and clashes took place with armed men who were apparently dissidents," the rights group said.
The Observatory said the army also launched an attack on Taum village, to the east.
"Several houses were partly destroyed and people were wounded... while the noise of heavy machineguns and explosions could be heard in several parts of the town and ambulances seen racing through the streets," it said.
In the southern province of Daraa, armed men -- also apparent defectors -- killed nine soldiers, one of them an officer, the Observatory said.
It said 25 civilians were arrested, including 12 members of one family.
In Brussels, the European Union decided to freeze the assets of the Commercial Bank of Syria, in a new set of sanctions over the regime's brutal crackdown on protesters, diplomats said.
"Today's decision is a direct consequence of the appalling and brutal campaign the Syrian regime is waging against its own people," said EU foreign policy chief Catherine Ashton.
According to the United Nations, the regime's crackdown on protests that began in mid-March has resulted in the deaths of more than 2,900 people.
Syrian authorities blame gangs of armed terrorists for the bloodshed.
"Our measures are not aimed at the Syrian people, but aim to deprive the regime of financial revenues and the support base necessary to maintain the repression," Ashton added, without naming the bank.
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Syrian authorities, meanwhile, organised a guided visit Thursday to Rastan, a centre of desertions within the army and scene of heavy clashes at the start of the month, where officials said the situation was returning to normal.
Roads in the city of Homs province, 185 kilometres (110 miles) north of Damascus, were deserted, shops closed and few pedestrians on the streets, an AFP correspondent said.
Journalists on the tour were shown an arms cache which officials said were seized as arrests were made.
In London, the Foreign Office summoned the Syrian ambassador to London over alleged intimidation of exiled activists, Foreign Secretary William Hague said.
"The Syrian ambassador was summoned to the Foreign Office this morning and told that any harassment or intimidation of Syrians in our country is unacceptable and will not be tolerated," Hague told parliament.
Back in Syria, rights group said security forces conducted fresh raids against anti-Assad demonstrators.
The Local Coordination Committees, which act as umbrella groups for protesters seeking to bring down the president, said soldiers and security forces also carried out a raid on Homs in central Syria where gunfire could be heard.
Security forces have set up checkpoints and made more than 50 arrests during raids in Qusayr, near the city of Homs, the Observatory said.
The London-based rights group later expressed "surprise at the "silence of the Syrian authorities on the killings of dozens of regular army soldiers in the past few days," including in Daraa, Deir Ezzor and Qusayr, near Homs.
On Wednesday, thousands of Syrians who back the president rallied in the centre of Damascus to show support for the regime which has faced seven months of anti-Assad protests.
In apparent response to the loyalist rally, anti-regime protests erupted in Idlib, in the port of Latakia, Homs, Deir Ezzor in the east, Daraa and near Damascus, the Observatory said.
On Wednesday, a court in the capital freed on bail prominent dissident Walid al-Bunni, who was arrested in August, his lawyer Michel Shammas said.
"The Damascus court of appeals on Wednesday freed opposition figure Walid al-Bunni in exchange for a bail of 1,150 Syrian pounds ($23). He will be tried later for inciting (anti-regime) demonstrations and sectarianism," he said.
Bunni was detained on August 6 along with his two sons, who were released shortly afterwards.