Some 70,000 Syrians took to the streets of Homs as Arab League observers visited the protest hub on Tuesday and activists said security forces shot dead 35 people across the country.

"More than 70,000 demonstrators tried to enter al-Saa square in the center of the city of Homs, while the security agents used tear gas to disperse them," said the Britain-based Syrian Observatory for Human Rights.

Saudi authorities have released seven Shiites detained after protests in the oil-rich Eastern Province earlier this year, activists said on Tuesday.

The group attended a "guidance session" by a Shiite cleric before leaving prison, the same sources said.

Iran opened a trial on Tuesday of an American of Iranian descent accused of spying for the U.S. Central Intelligence Agency, the Fars news agency reported.

"The first hearing in the trial of Amir Mirzai Hekmati, recently arrested for spying for the United States, started Tuesday morning" in a Tehran court, Fars reported.

A gunman shot dead at least one student and wounded four others at Damascus University on Sunday, Syrian state media reported, in an attack activists blamed on pro-regime students.

The assailant, identified as student Ammar Balush, went on the shooting spree with a handgun during exams at the biomedical faculty, said the official SANA news agency.

Pirates hijacked an Italian chemical and oil tanker with six Italians, five Ukrainians and seven Indians on board at dawn on Tuesday off Oman in an area where Somali pirates operate, officials said.

"It was attacked at four or five in the morning. There were 18 people on board," Domenico Ievoli, the Naples-based owner of the ship, Marnavi, told Agence France Presse.

Kuwait's public prosecutor released 32 stateless people on bail on Tuesday after holding them for nine days for taking part in a protest to demand citizenship, their lawyer said.

"The prosecutor has just ordered their release on bail of $720 each. We are currently undertaking the necessary procedures to free them," Ali al-Sabri told Agence France Presse.

Al-Qaida's Iraq franchise claimed responsibility for a wave of bombings last week that killed scores of people and heightened sectarian tensions days after the withdrawal of U.S. troops.

The self-proclaimed "Islamic State of Iraq," inspired by the late Osama bin Laden, issued a statement Monday referring to "Thursday's Invasion" and vowing to protect Iraq's Sunni Muslims from an "Iranian project."

Arab League observers have arrived in the flashpoint Syrian city of Homs but are unable to do their job, the head of the country's main opposition group said on Monday.

Syrian National Council (SNC) head Burhan Ghalioun told reporters at a Paris news conference that some of the observers were in the besieged city "but they are saying they cannot go where the authorities do not want them to go."

The United Nations' top envoy in Iraq, German diplomat Martin Kobler, does not expect civil war to break out in the country, he was quoted as saying on Monday.

"The country is facing significant security problems," he said, pointing to a string of attacks since last week that have claimed dozens of lives.

Egypt's prosecutor general on Monday referred two Israelis and a Ukrainian accused of arms smuggling to the Emergency Supreme State Security Court, his office said.

The Ukrainian and one Israeli are in custody, while the other Israeli will be tried in absentia, the prosecutor's office said in a statement.