U.S. accusations Iran was involved in an alleged plot to kill the Saudi ambassador to Washington is a "childish game" meant to distract the U.S. public's attention, Iran's parliament speaker said Wednesday.

"The Americans have launched a stupid mischief. They want to divert attentions from the problems in the region," Ali Larijani said, according to Mehr news agency and other Iranian media.

Thousands of people rallied in central Damascus on Wednesday in a show of support for the regime of Syrian President Bashar Assad which has been shaken by mass protests for nearly seven months.

An Agence France Presse journalist witnessing the demonstration said it had begun with a call on the Facebook page "My homeland, Syria" of Assad supporters urging them to rally to "reinforce unity and solidarity with the families of martyrs and thank Russia and China for their stand against the conspiracy" targeting Syria.

Bomb and gun attacks mainly targeting security forces, including two suicide car bombs minutes apart on police stations, killed at least 19 people in Baghdad's deadliest day in more than a month.

The violence, in which nearly 70 people were also wounded, signaled insurgents' ability to plan and carry out coordinated attacks on well-secured targets, as Iraq weighs its options over a post-2011 American military training mission.

Saudi King Abdullah will undergo new back surgery in Riyadh in the next few days, following two similar operations last year in the United States, the palace said in a statement on Tuesday.

Exams performed after the 87-year-old king complained of "pain in the lower back" revealed a stretched ligament, said the statement quoted by the Spa official news agency.

The United States said Tuesday it had busted a plot conceived at high levels of Iran's revolutionary leadership to kill the Saudi envoy to Washington in a major terror attack, and vowed to hold Tehran to account.

An aide to Iran's President Mahmoud Ahmadinejad later on denied allegations that the Islamic republic was involved in such plot.

Israeli and Hamas officials announced late Tuesday that they have reached a prisoner swap deal to free a captured Israeli soldier held in the Gaza Strip in exhange for hundreds of Palestinian prisoners, capping five years of painful negotiations that have repeatedly collapsed in fingerpointing and violence.

The deal would bring home Sgt. Gilad Schalit, who was captured in a cross-border raid in June 2006 by Palestinian militants who burrowed into Israel and dragged him into Gaza. Little has been known about his fate since then.

Egyptian Deputy Prime Minister Hazem al-Beblawi resigned on Tuesday following deadly clashes in the capital that left 25 people dead, the official MENA news agency reported.

Beblawi -- one of two deputy prime ministers who also has the finance portfolio -- said he tendered his resignation after Sunday's deadly clashes "which shook the security of the society, which is the government's responsibility" to ensure.

Libya's new regime fighters Tuesday seized the police headquarters in the center of Moammar Gadhafi's hometown Sirte after the toppled leader's diehards deserted it, an Agence France Presse reporter said.

The National Transitional Council combatants celebrated the takeover of the strategic security building by honking the horns of their vehicles and firing into the air.

Kuwait's foreign minister told reporters Tuesday the Arab world's foreign ministers are to meet to discuss developments in Syria.

"There will be a meeting of Arab foreign ministers to study the events in Syria," Sheikh Mohammed al-Sabah told a news conference in Kuwait's capital, without specifying the date for the gathering.

Israeli forces on Tuesday demolished for the third time a mosque in a remote Bedouin village in the Jordan valley, Palestinian security forces said.

The demolition took place in the village of Khirbet Yarza, some five kilometers east of Tubas in the northeastern corner of the West Bank.