- At least five people are killed Thursday, activists say
- Security forces pound and storm towns in Idlib province
- The U.N. estimates that the Syrian conflict has killed more than 9,000 people
- Security forces also target Damascus and its countryside
(CNN) -- U.S. Secretary of State Hillary Clinton joins world leaders this week in the latest effort to end bloodshed in Syria as pressure mounts for the nation's embattled leader to implement a peace deal.
Syria signed off this week on a peace initiative by U.N.-Arab League special envoy Kofi Annan.
Despite the peace deal, security forces shelled and stormed various towns early Thursday, leaving at least five people dead, the opposition Syrian Observatory for Human Rights said.
"There is no indication whatsoever that the Assad forces are complying with the Annan plan," said Fadi Yasin, an activist in Idlib province.
Yasin said troops pounded Jabal Zawiya in Idlib and stormed towns in the province Thursday morning after shelling homes near Maaret Nouman.
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Can Syria conflict be stopped? "We have also witnessed reinforcements that arrived to the city of Idlib," he said. "Frankly, whoever sees the amount of military presence in the cities would say that the regime speaks one language on the ground and another at the political level. They are just spewing lies. ... we do not really trust their promises."
Security forces also targeted Damascus and its countryside in an assault aimed at depriving the area of essential humanitarian needs including food and medical supplies, activists said.
The United Nations estimates that the Syrian conflict has killed more than 9,000 people since a government crackdown on protesters began last March. Opposition activists put the toll at more than 10,000.
Leaders reacted hopefully but skeptically to Syria's initial acceptance of the peace plan Tuesday because al-Assad has made other commitments calling for an end to violence.
The plan calls for an end to the violence by the government and opposition; timely humanitarian aid; speeding up the release of "arbitrarily detained" people; ensuring "freedom of movement" for journalists; and respecting peaceful demonstrations and "freedom of association."
The latest diplomatic effort will include Clinton meeting with Gulf officials in Saudi Arabia on Friday and Saturday in an effort to end the bloody crackdown by President Bashar al-Assad's troops against anti-government protesters.
While in Riyadh, she will discuss regional issues, including the bloodshed in Syria, with King Abdullah and other leaders.
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Peace plan working in Syria? Clinton will also be in Istanbul on Saturday and Sunday to meet the "Friends of the Syrian People."
"This meeting will build upon steps that our friends, allies, and the Syrian opposition continue to take in an attempt to halt the slaughter of the Syrian people and pursue a transition to democracy in Syria," the State Department said in a statement.
Syria routinely blames "armed terrorist groups" for violence in the country while most reports from inside the nation suggest the government is slaughtering civilians in an attempt to wipe out dissidents.
CNN cannot independently confirm reports from inside Syria because the government severely restricts access by international journalists.
U.S. State Department spokeswoman Victoria Nuland called on the regime to act quickly.
"It is clear that the Assad regime has not yet taken the necessary steps to implement the commitment it has made to Kofi Annan," she said. "He knows what he needs to do. We will judge him by his actions, not by his promises."
The regime is not serious about implementing the proposal, said Dima Moussa, a spokeswoman for the Revolutionary Council of Homs.
"As far as we know, the Syrian regime has taken none of the steps laid out in the six-point peace plan mapped out by Kofi Annan," she said.
Annan plans to brief the U.N. Security Council in a closed meeting Monday. Syria is expected to be a hot topic at this week's Arab League summit in Baghdad.
CNN's Amir Ahmed and Joe Sterling contributed to this report.
