Military operations in Syria killed at least four civilians on Wednesday in an unrelenting crackdown on dissent as a pro-democracy protest movement entered its sixth month, activists said.

The central committee of the ruling Baath party, which has been in power since 1963, met for the first time since protests against President Bashar al-Assad's regime erupted in mid-March, pro-government daily Al-Watan said.

Syrian diplomats are intimidating expatriates who speak out against the regime, and reporting back home where dissidents' relatives are then threatened and arrested, according to Wednesday's Wall Street Journal.

The Obama administration told the Journal it had "credible" evidence that the regime of Syrian President Bashar Assad is using the reports from its embassies abroad to target relatives of those living overseas, particularly Syrian-Americans who have joined peaceful U.S. protests.

Prime Minister Najib Miqati stressed on Wednesday the relevant authorities in Lebanon did their best in their attempt to arrest the four suspects named in the indictment issued by the Special Tribunal for Lebanon probing the assassination of ex-PM Rafik Hariri.

“The relevant authorities have been looking for the various people on a daily basis,” Miqati told Newsweek U.S. weekly news magazine.

U.S. Secretary of State Hillary Clinton said Tuesday that Turkey, Saudi Arabia and other governments should call on Syrian President Bashar al-Assad to step down, but declined to make that call herself.

"It's not going to be any news if the United States says Assad needs to go," Clinton said, suggesting the world's reaction to such a move would be, "Ok, fine. What's next?"

Dozens of Syrian army vehicles left the eastern protest hub of Deir Ezzor on Tuesday after a 10-day operation in which activists say up to 30 people were killed, an Agence France Presse journalist on a government tour of the city reported.

"The army conducted a quick and sensible operation in Deir Ezzor in order to restore stability and calm at the request of residents," who complained of "armed groups," an officer told reporters.

Advocacy group Human Rights Watch on Tuesday said it had urged the European Union to freeze the assets of the Syrian National Oil Company, Syrian National Gas Company, and the Central Bank of Syria until Damascus "ends gross human rights abuses against its citizens."

"Syria’s authorities are still killing their own people despite multiple efforts by other countries, including former allies, to make them stop," said Lotte Leicht, EU director at the New York-based HRW.

Heavy machine-gun fire reverberated Tuesday across the Syrian Mediterranean port of Latakia, which is engulfed by a major military offensive, activists said.

"The heavy machine gun-fire and bullets were intense in areas of Latakia, Ramel, Masbah al-Shaab and Ain Tamra for more than three hours," said the Syrian Observatory for Human Rights.

Iran sees no justification for any Western intervention in the "internal affair" of its regional Arab ally Syria, foreign ministry spokesman Ramin Mehmanparast said on Tuesday.

"The events in Syria are its internal affair and there is no justification for any foreign intervention as it can only create many problems," Mehmanparast said during his weekly press briefing.

Syrian refugees are fleeing the crackdown in their towns into villages in northern Lebanon before sunset and returning at dawn to escape the raids launched overnight on their homes, the pan-Arab daily Asharq Awsat reported on Tuesday.

Sources told the newspaper that “more than 100 families are emigrating at sunset every day and temporarily from al-Qusayr, Heit, Bouiet and al-Soummaqiyat to the towns of Akroum, al-Nousoub, Houlwas, el-Kneisse and Wadi Khaled.”

The United States said Monday it was working with "a broad array" of other countries to pressure Syrian President Bashar al-Assad to end the "outright murder of his own people."

Assad "has to cease the systematic violence, mass arrests, and the outright murder of his own people," White House spokesman Jay Carney told reporters.