Nearly half a million people jammed the streets of the flashpoint Syrian city of Hama as activists said at least 13 people were killed nationwide Friday in the continuing backlash against President Bashar al-Assad.

At least six deaths took place in the Damascus suburb of Dumair, where activists say security forces shot demonstrators. They say deadly shootings also occurred in cities including Homs and Maaret al-Numan.

The Syrian government blamed “armed gangs” for some of the deaths. Also, the state-run SANA news agency says pro-government rallies took place in several cities.

Activists say Syrian security forces were tempered in Hama by the presence of the U.S. and French ambassadors who traveled to express solidarity with protesters.

An activist told VOA that the U.S. ambassador to Syria, Robert Ford, was given videos from residents showing alleged human rights violations by Syrian forces.

Ford and French envoy Eric Chevallier met with Hama residents but left before Friday's protest began. U.S. State Department spokeswoman Victoria Nuland says their visits had not been coordinated in advance.

On Thursday, the Syrian Foreign Ministry said that Ford's presence in Hama without prior permission was “clear evidence” of a U.S. attempt to “increase tension and damage Syria's security and stability.”

Rights groups say Syrian security forces have killed at least 1,400 civilians since mid-March while trying to suppress the anti-government uprising.

The Syrian government says terrorists and Islamist militants have killed hundreds of security personnel during the same period.