Damascus on Wednesday rejected a call by U.N. chief Ban Ki-moon for it to declare a unilateral ceasefire, insisting that rebels fighting the government must stop the violence first.

"We told Ban Ki-moon to send emissaries to the countries which have influence on the armed groups, so that they put an end to the violence," foreign ministry spokesman Jihad Maqdisi said.

Israel's Benjamin Netanyahu on Wednesday kicked off his re-election bid after calling snap polls that he is tipped to win, presenting himself as the only hope of facing Iran and the world economic crisis.

Following his announcement late on Tuesday that the election was to be brought forward, Netanyahu fired the unofficial starting gun to a campaign expected to see Israelis go to the polls in January or February.

A Syrian cameraman working for an official television channel was shot dead "by terrorists" on Wednesday in the eastern province of Deir Ezzor, his broadcaster announced.

Cameraman Mohammed al-Ashram "was killed by terrorists" in Deir Ezzor, the largest city in eastern Syria, Al-Ikhbariya director Imad Sara told AFP, using the Syrian regime's blanket term for armed rebels.

Jordan's King Abdullah II on Wednesday designated veteran politician Abdullah Nsur to form a new government after prime minister Fayez Tarawneh and his government resigned ahead of legislative polls.

"The king today accepted the resignation of Fayez Tarawneh's government and asked Nsur to form a new government," a senior palace official told AFP.

Syria's main exiled opposition coalition the Syrian National Council will in a "matter of days" set up in a rebel-controlled area inside the country, a top member of the group said on Wednesday.

"Very soon, we will install ourselves in Syria, deep in Syrian territory. It's a matter of days," Jamal al-Ward, a SNC official in charge of relations with the rebel Free Syrian Army (FSA), told AFP.

Turkey's top military commander on Wednesday warned of a stronger response if Syrian shells continued to land on Turkish soil, the private NTV television network reported amid fears of a cross-border escalation of Syria's civil war.

"We have retaliated (for Syrian shelling) and if it continues, we'll respond more strongly," Armed forces chief of staff General Necdet Ozel said in Akcakale, a border town where five civilians were killed by Syrian shelling last week.

Syrian forces on Wednesday hammered rebel belts in the central city of Homs, where besieged residents desperately pleaded for humanitarian assistance, and in the northern city of Aleppo, a watchdog said.

Shells rained down from early morning on parts of Homs and on the nearby town of Qusayr, near the Lebanon border, the Syrian Observatory for Human Rights said.

The U.S. military has sent a task force to Jordan to help it handle an influx of Syrian refugees and prepare for scenarios including loose chemical weapons, The New York Times reported Wednesday.

The Times said the 150-strong force of planners and specialists -- led by a senior U.S. officer -- was looking at ways to prevent the increasingly bloody Syrian civil war from spilling across Jordan's borders.

The chief of U.S. intelligence has rejected criticism over how spy agencies responded to a deadly attack on diplomats in Libya and said there was no clear warning before the onslaught.

Pushing back against allegations from Republican lawmakers, Director of National Intelligence James Clapper suggested Tuesday it was naive to believe the government could have quickly arrived at a definitive explanation of last month's attack on the U.S. consulate in the eastern Libyan city of Benghazi.

British police on Wednesday said they had arrested two people at London's Heathrow Airport on suspicion of the commission, preparation or instigation of acts of terrorism.

A man and a woman, both aged 26, were detained by officers from the counter-terrorism command at 8.30 pm (1930 GMT) Tuesday after arriving on a flight into the airport, according to a Metropolitan Police statement.