They said two other protesters were shot dead late Thursday night.
The gunfire continued unabated, even though Assad told U.N. Secretary-General Ban Ki-moon that military and police operations had stopped, according to a statement issued by the United Nations. The harsh statements by President Barack Obama and European leaders also appeared to have no immediate effect.
The London-based Syrian Observatory for Human Rights and The Local Coordination Committees, a group that documents anti-regime protests, said demonstrations took place in areas including the capital Damascus, central city of Homs, southern province of Daraa, coastal city of Latakia and eastern city of Deir el-Zour.
The observatory and the LCC said two protesters were shot dead Friday afternoon in the villages of Hirak and Inkhil in the southern province of Daraa.
The shooting was accompanied by a wave of arrests in several parts of Syria. Despite the crackdown thousands of people protested Thursday night demanding Assad's ouster, activists said.
The observatory and The LCC said Thursday's shooting killed one person in a Damascus suburb and other died of his wounds early Friday in the central city of Homs.
Syrian state TV said four policemen were wounded by gunmen in Inkhil on Friday.
Rami Abdul-Rahman, who heads the observatory, said there was wide security deployment in many parts of the country. The military positioned armored personnel carriers in some areas. Citing witnesses, Abdul-Rahman said army checkpoints were set up as usual in the northwestern region of Jabal al-Zawiya in Idlib province.
"I've seen soldiers walking through the streets of the city," said an activist in Homs who asked that her name not be mentioned for fear of government reprisals. "But I can't hear gunfire, and I don't believe they are shooting."
Assad is coming under mounting criticism for his crackdown on a 5-month uprising. Human rights groups and witnesses accuse Syrian troops of firing on largely unarmed protesters and say more than 1,800 civilians have been killed since mid-March.
Activists posted an amateur video online Friday showing two soldiers in uniform slapping and kicking about a dozen detainees inside a bus and forcing them to chant "our souls, our blood we sacrifice for you Bashar," and "God, Syria and Bashar only."
The Associated Press could not verify the videos. Syria has banned most foreign media and restricted local coverage, making it impossible to get independent confirmation of the events on the ground.
In a stinging written statement, President Barack Obama said Thursday that Assad has overseen a vicious onslaught of his people as they protest for freedom. It was Obama's first explicit call for Assad to step down.
Obama said Assad's calls for reform ring hollow while he is "imprisoning, torturing and slaughtering his own people." Obama also signed an executive order that gives his administration authority to impose sweeping new sanctions on Syria intended to further isolate Assad.
The leaders of France, Britain and Germany issued a statement saying Assad should "leave power in the greater interests of Syria and the unity of his people."
In a report released in Geneva, a U.N. team said the violence in Syria should be referred to the International Criminal Court. Crimes against humanity are considered the most serious of all international human rights violations after genocide.