Arab League chief Nabil al-Arabi rejected any foreign intervention in Syria on Thursday as he joined European Union talks aimed at ramping up pressure on the regime over its crackdown on dissidents.

"We reject any accusation that the Arab League is inviting any intervention," Arabi said on arrival for a lunch with EU foreign ministers, who slapped a new round of economic sanctions on Damascus.

Washington on Thursday placed economic sanctions on a senior Syrian general and a financier uncle of President Bashar al-Assad, adding new pressure on the regime over its bloody political crackdown.

The Treasury Department added Mohammed Makhlouf, Assad's maternal uncle and the father of already-sanctioned telecoms magnate Rami Makhlouf, and 4th armored division General Aus Aslan, to its growing list of Syrian figures and organizations that Americans are banned from doing business with.

Syria has suspended its participation in the Mediterranean Union in retaliation for punitive measures against its regime by European states, state media said on Thursday.

"Syria is suspending its membership in the Mediterranean Union in response to European measures taken against it," said a statement carried by the official SANA news agency.

The number of people killed in Syria following a crackdown on protesters since March has reached at least 4,000, the U.N. rights chief said on Thursday, as the European Union tightened sanctions against Syria's energy and financial sectors.

"We are placing the figure at 4,000. But the information coming to us is that it's much more," said United Nations High Commissioner for Human Rights Navi Pillay during a conference in Geneva.

A government of unity will be announced in Yemen before Sunday, the opposition said, in line with a peace deal that is to see President Ali Abdullah Saleh step down from power.

"There is a deal with the ruling party on the distribution of posts. Forming a cabinet will be very easy," Mohammed Qahtan, spokesman for the parliamentary opposition coalition, told Agence France Presse.

Kuwait on Thursday appealed to its nationals to leave Syria and refrain from travelling there because of safety concerns amid a deadly eight-month crackdown on democracy protests.

"The foreign ministry calls on citizens currently present in Syria to leave for their own safety," it said in a statement quoted by the state-run KUNA news agency.

Syria's civilian opposition and army rebels have agreed to coordinate their struggle against President Bashar Assad's regime, an official said Thursday.

The first meeting between the Syrian National Council and the Free Syrian Army earlier this week in Turkey appeared to mark a change of tack from the SNC's previous reluctance to back the armed struggle.

Kuwait's public prosecutor on Thursday ordered the release on bail of 24 youth activists who had been held in detention over the storming of parliament last month, their lawyer said.

"A decision has just been issued to release all the 24 people on a bail of 1,000 dinars ($3,600) each," al-Humaidi al-Subaie, who heads the legal defense team of the activists, told Agence France Presse.

Amnesty International and rights activists on Wednesday called on the U.N. Security Council to refer the Syrian government's deadly crackdown on protests to the International Criminal Court.

A Syrian activist forced into exile by President Bashar Assad's government said there has to be "regime change" in the country, but with no foreign intervention.

Amnesty International has accused Saudi Arabia of conducting a campaign of repression against protesters and reformists since the Arab Spring erupted, in a newly published report.

"The last nine months has seen a new wave of repression in Saudi Arabia as authorities have cracked down on protesters and reformists on security grounds," the rights watchdog said in a statement issued late Wednesday.