ALEPPO: Syrian troops and rebels clashed on Friday in the city of Aleppo, where several people died when a shell crashed into a bakery as hundreds of residents queued for bread, AFP correspondents said.
They said around a dozen people, including three children, were killed and 20 wounded at the bakery in the eastern Tariq al-Bab district of the increasingly desperate northern city.
And troops repelled a rebel attack on Aleppo's international airport, state news agency SANA reported. "Mercenary terrorists" had tried to attack it but the "army hit back and killed most of them."
In the latest clashes, Aleppo's historic Citadel, part of a UNESCO-listed world heritage site, was heavily damaged by bombing, the opposition said.
The violence raged on as world powers prepared to name veteran Algerian diplomat Lakhdar Brahimi as their new envoy to seek an end to a 17-month uprising that has cost more than 21,000 lives.
Secretary of State Hillary Clinton arrived in Istanbul for talks with Turkish leaders as the U.S. warned that Syria's allies Iran and Hezbollah could be planning attacks on Western targets, with Washington imposing fresh sanctions on the regime and on the Lebanese militant group Hezbollah.
A rebel commander, Hossam Abu Mohammed, said his men were still fighting in parts of Aleppo's southwestern district of Salaheddin after most fled on Thursday in the face of heavy bombing and advancing troops.
"We will not let Salaheddin go," the Free Syrian Army's Abu Mohammed told AFP by telephone on the third day of a government offensive to take the city.
The army again bombed parts of Salaheddin, as well as the Sakhur and Hanano districts in the northeast, the Syrian Observatory for Human Rights said.
At least 103 people were killed nationwide on Friday, including 55 civilians, the watchdog said. One of those killed was a 19-year-old protester shot dead by regime forces in Aleppo.
In the central city of Homs, the army pounded the rebel stronghold of Khaldiyeh with "dozens" of people killed or wounded, the Observatory said.
Before dawn, a MiG 21 fighter jet dropped four bombs on rebel positions in Hanano, an AFP correspondent said. One struck the courtyard of an FSA compound and another struck a nearby house, wounding a number of people.
The opposition Syrian National Council said Aleppo's 13th-century Citadel, part of a complex of sites in the city's historic heart that the U.N. Educational, Scientific and Cultural Organisation says is of "outstanding universal value," had been damaged in army shelling.
It was not possible to independently verify the claim.
Also on Friday, rebels captured three journalists who work for Syrian public television Ikhbariya as they accompanied government troops operating near Damascus, the Observatory said.
Ikhbariya later said it had lost contact with its crew.
-- 'Syrians clamouring for peace' --
Clinton arrived early Saturday in Turkey, a former ally of Syria which has now turned against Assad, for in-depth discussions with its leaders on "planning for the day after Assad falls," a State Department official said.
In a bid to starve the regime of much-needed revenue, the United States slapped sanctions on the Syrian state oil marketing company Sytrol for trading with Iran.
And the U.S. Treasury said it was adding Lebanon's Hezbollah to a blacklist of organisations targeted under Syria-related sanctions.
But a senior U.S. security official warned the Western pressure might not succeed without cost, with Iran and Hezbollah allegedly plotting revenge attacks on Western or Israeli targets.
"Our assessment is that Hezbollah and Iran will both continue to maintain a heightened level of terrorist activity in operations in the near future," said Daniel Benjamin, the U.S. State Department's counter-terrorism coordinator.
"We are increasingly concerned about Hezbollah's activities on a number of fronts, including its stepped up terrorist campaign around the world," he said.
"Hezbollah's extensive support to the Syrian government's violent suppression of the Syrian people exposes the true nature of this terrorist organization," said David Cohen, a senior US Treasury official.
Meanwhile, diplomats at the United Nations said former Algerian foreign minister Brahimi was expected to be named as the new U.N.-Arab League envoy to Syria early next week.
Kofi Annan, a former U.N. secretary general, resigned from the post of envoy, saying he had not received enough international support for his efforts to end the conflict but is staying on until August 31.
In a statement released by The Elders, a group of world statesmen, Brahimi said "the U.N. Security Council and regional states must unite to ensure that a political transition can take place as soon as possible."
"Millions of Syrians are clamouring for peace. World leaders cannot remain divided any longer, over and above their cries."
Britain said on Friday it would give the rebels five million pounds ($7.82 million, 6.3 million euros) in non-lethal assistance, including body armour and communications equipment.
Meanwhile the International Committee of the Red Cross said the Syrian Red Crescent had suspended most of its work in Aleppo because of the extreme danger.
A statement in Geneva said the ICRC had managed on Thursday to deliver food and other essentials to cover the needs of at least 12,500 people in the city of some 2.7 million people.
Meanwhile the imam of the Grand Mosque in Mecca, Islam's holiest site, warned that a "genocide" was underway in Syria and urged participants at an Islamic summit to take place on Tuesday to take action against the Syrian regime.
Mosques and Islamic centres across the United States also came together on Friday to condemn the Syrian regime's brutal crackdown and raise funds for civilians trapped in the conflict.