British prime minister David Cameron has recalled parliament early on Twitter for an urgent debate on Syria.

The MPs have been called back from their summer break four days early to attend the House on Thursday. More than 60 MPs had signed a parliamentary motion urging a recall to formally debate what Britain should do in response to the gas attack in which hundreds died.

The government has no legal obligation to do so as the prime minister can use the Royal Prerogative to deploy ground troops.

UN inspectors with a mandate of investigating the chemical weapon attack in the Ghouta region have postponed their next site visit until Wednesday over safety fears, according to a UN statement.

"Following yesterday's attack on the UN convoy, a comprehensive assessment determined that the visit should be postponed by one day in order to improve preparedness and safety for the team. Considering the complexities of the site, confirmation of access has not been obtained but is expected later today." it said.

The UN experts came under sniper fire on their way to a site visit on Monday.


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