An accidental blast at Iran's Abadan's oil refinery killed at least one person and injured more than 20 during a visit Tuesday by President Mahmoud Ahmadinejad, who was not affected and went on to make a televised speech, reports said.

"A technical fault led to an explosion in one of the units of this refinery," Fars news agency said, referring to the oil facility in the southwestern city of Abadan.

Israeli Prime Minister Benjamin Netanyahu Monday vowed that the Jewish state would never withdraw to the "indefensible" 1967 border, revisiting a spat over the issue with U.S. President Barack Obama.

Netanyahu told the powerful pro-Israel lobby said he would spell out his vision for peace with the Palestinians in a speech to Congress on Tuesday, but promised that would not include a withdrawal to lines that existed before the 1967 Six Day War.

Six people were killed and dozens wounded during armed clashes in Sanaa on Monday between police and supporters of powerful opposition tribal chief Sadiq al-Ahmar, tribal sources and state media said.

The clashes came a day after President Ali Abdullah Saleh refused to ink an accord brokered by the Gulf Cooperation Council (GCC) under which he would cede power within 30 days in exchange for immunity from prosecution for himself and his aides.

The European Union, welcoming U.S. President Barack Obama's Middle East policy shift, Monday called for an "early meeting" of the Quartet group of world powers seeking an Israeli-Palestinian peace deal.

It also welcomed the recent reconciliation between rival Palestinian leaders from Fatah and Hamas and reiterated readiness to recognize a Palestinian state "when appropriate".

The United States on Monday called on Moammar Gadhafi to leave Libya as Washington's most senior envoy to date held talks in the rebel capital in another boost to forces fighting to oust the strongman.

Washington's call came a day after the European Union opened an office in the rebel bastion of Benghazi to show its "long term" support to the rebels who took their diplomatic offensive to NATO's sole Muslim member Turkey.

The EU tightened its sanctions on Iran on Monday, adding more than 100 firms to a blacklist of companies hit by an assets freeze over Tehran's disputed nuclear program, diplomats said.

EU foreign ministers adopted the new restrictive measures amid efforts to jump start international talks aimed at convincing Iran to halt its nuclear activities.

Europe tightened the noose on President Bashar al-Assad Monday, imposing sanctions on the Syrian leader for the first time while calling for quick Middle East peace talks as it responded to the Arab Spring.

Long reluctant to target the Syrian leader directly, the European Union's decision to slap an assets freeze and travel ban on Assad is the latest in a string of measures against his regime, though the effects are unclear.

Ministers from the Gulf Cooperation Council (GCC) announced Sunday they had suspended mediation efforts in Yemen, after the country's president failed to sign a transition deal for him to quit office.

The GCC had "decided to suspend their initiative in the absence of the propitious conditions," said a statement issued from Riyadh.

Funerals were held on Sunday for victims of a fierce Syrian government crackdown on anti-regime protests that killed about 50 people in two days, five of them in a funeral procession, activists said.

In the city of Homs, an epicenter in central Syria of the nine-week uprising against President Bashar al-Assad's regime, hundreds of protesters took to the streets, chanting "down with the regime," an activist said.

U.S. President Barack Obama vowed Sunday to "keep up pressure" on Iran to prevent it from obtaining nuclear weapons and forcefully defended his call for an Israeli-Palestinian peace based on pre-1967 frontiers, suggesting critics had misrepresented him.

Outlining U.S. and U.N. sanctions imposed on Iranian President Mahmoud Ahmadinejad's regime, Obama said Iran is now "virtually cut off from large parts of the international financial system."