China on Tuesday refused to commit to attend an international conference in Tunis this week after Russia said it would boycott the meeting aimed at seeking political change in Syria.

The Friends of Syria group will meet for the first time on Friday after being created in response to a joint veto by China and Russia of a U.N. Security Council resolution condemning a bloody crackdown on protests in Syria.

Iraq will quickly approve the nomination of a non-resident Saudi ambassador, meaning the kingdom will have an ambassador to Iraq for the first time since 1990, the Iraqi premier's spokesman said Tuesday.

"Iraq's response accepting this request will be quick," Iraqi Prime Minister Nouri al-Maliki's spokesman Ali Moussawi told Agence France Presse.

Two Iranian warships sent by Tehran to the Mediterranean last week to help "train the Syrian navy" entered the Suez canal early on Tuesday on their way back to Iran, a canal authorities source told Agence France Presse.

The ships, a destroyer and supply vessel, came from the Syrian port of Tartus and were heading south towards the Red Sea, the source said, adding that they were due to complete their transit of the canal by Tuesday afternoon.

Four people including a child were killed in clashes Tuesday in south Yemen between security forces and separatists, who have called for "civil disobedience" in protest at the country's presidential polls, officials and medics said.

A 10-year-old child was killed when militants from the separatist Southern Movement traded gunfire with police near the election commission headquarters in Aden's Dar Saad neighborhood, residents and medics said.

Syrian forces killed 57 civilians Tuesday as they blitzed the city of Homs and a village in Idlib province, monitors said, as the Red Cross sought a truce to deliver aid and the United Nations demanded unimpeded access for aid groups.

The escalation comes as Russia, a key ally of President Bashar al-Assad's regime, said it will boycott an international conference in Tunis this week aimed at seeking political change in Syria and China refused to commit.

Russia on Tuesday said it will not attend an international conference in Tunis this week aimed at seeking political change in Syria because the meeting only supported the opposition's cause.

The meeting was called "for the purpose of supporting one side against another in an internal conflict," the foreign ministry said in a statement. "We cannot accept the offer to attend this meeting."

Yemen's future president Abdrabuh Mansour Hadi hailed Tuesday's election, in which he is the sole candidate, as a "historic day" that would open a new page for the country, as he cast his ballot amid tight security.

"This is a historic day in Yemen. We will turn the page of the past and open a bright new page on which we will write the future of a new Yemen," Hadi told reporters, as he posted his ballot into a box at a polling station in Sanaa amid applause.

Iraq's interior ministry said on Monday its forces had fended off "smugglers and infiltrators" trying to cross the border from Syria.

"Border guards were able to fend off groups of smugglers and infiltrators who were trying to cross the border from Syria into Iraq," a statement on the ministry's website said, without specifying when this occurred.

Top Republican U.S. Senator John McCain called on Monday for Syria's opposition to be given weapons to help "defend themselves" against President Bashar al-Assad's forces, while excluding direct U.S. aid.

"I'm not calling for the direct supply of weapons by the United States of America," he told a news conference in Cairo.

Outgoing President Ali Abdullah Saleh urged Yemenis to vote for his successor Abdrabuh Mansour Hadi in Tuesday's referendum-like elections to ensure a "peaceful" transition of power, state media reported.

"I invite you to actively participate in this democratic event and to head to ballot boxes to vote for Abdrabuh Mansour Hadi" as future president, Saleh said in a speech addressed to Yemenis, published by the Saba news agency.