America is setting up a new crisis unit to deal with "worst case" scenarios in Syria, including chemical weapons attacks that could require the imposition of a no-fly zone.

During a visit to Syria´s neighbour, Turkey, the US secretary of state, Hillary Clinton, said that America and Turkey were creating a formal working group to provide "very intensive operational planning" for the Syria crisis.

The group will coordinate military, intelligence and political responses to the potential fallout in the case of a chemical attack, which could result in huge numbers of casualties and a further influx of refugees into Turkey.

"We have been closely coordinating over the course of this conflict, but now we need to get into the real details of such operational planning. It needs to be across both of our governments," Mrs Clinton told a news conference on Saturday after a meeting with the Turkish foreign minister, Ahmet Davutoglu.

Asked by a reporter if such discussions included imposing a no-fly zone to protect territory controlled by rebels, Mrs Clinton indicated that it was a possible option. "The issues you posed within your question are exactly the ones the minister and I agreed need greater in-depth analysis," she said, although she said no decisions were imminent.

"It is one thing to talk about all kinds of potential actions, but you cannot make reasoned decisions without doing intense analysis and operational planning," she said.

In remarks that showed Washington´s bleak assessment of the future of the conflict, she added that the outside world had to prepare itself for "the horrible event that chemical weapons (are) used".

"What would that mean in terms of response, humanitarian and medical emergency assistance and, of course, what needs to be done to secure those stocks from ever being used or falling into the wrong hands?" she asked.

Her remarks come just days after a senior aide to the US president, Barack Obama, refused to rule out the eventual creation of a no-fly zone over the northern terrorities of Syria controlled by rebel forces. John Brennan, Mr Obama´s senior counter-terrorism adviser, said that nothing was "off the table."

Meanwhile, fighting continued across Syria, with fresh clashes in the capital, Damascus, as well as in the country´s second city, Aleppo, where fighting has now been raging for three weeks.

Syrian forces pounded a suburb of Damascus with mortars and artillery shells, a day after local rebels abducted a pro-government television crew, according to activists. It was the latest attack on pro-regime media and the latest abduction blamed on rebels in Syria´s escalating civil war. The television station blamed "terrorists" and said that efforts were under way to release them. (© Copyright of Telegraph Media Group Limited 2012. 08/11/12)