'Little doubt' of Syria gas attack

US Senator John McCain said Washington should take "serious action" against Syria, and suggested launching cruise missiles. Speaking in South Korea, he said:

"We know for sure that he's used them at least once, now here is the second time, horrific, horrific.

"And if the United States stands by, and doesn't take very serious action, not just launching some cruise missiles, then again, our credibility in the world is diminished even more, if there is any left. "

Russia could persuade Assad regime to return the chemical weapons they probably bought from them to reduce the international tension surrounding Syria, a security expert suggested.

Dr Sally Leivesley said Russia and Syria had a "cradle to grave" relationship which could be used to stem the growing tension after last week's chemical attack.

Russia is deeply concerned over possible US military action in Syria, urging restraint, said state news agency RIA citing Foreign Minister Sergei Lavrov.

The CBS White House correspondent Mark Knoller has tweeted that the White House is refuting claims of intervention in Syria.

The United States now has little doubt the Syrian government used chemical weapons against civilians last week, a senior official told Reuters.

The official added that the president was now focused on "assessing the facts" to enable him to make an informed decision as to how to respond.

The White House has said there is 'Very little doubt' chemical weapon have been used by Syria regime against civilians.

Gulf-based supporters have sent a 400-ton shipment of arms to Syria's outgunned rebels, one of the biggest to reach them in their two-year-old uprising, opposition sources said on Sunday.

The consignment - mostly ammunition for shoulder-fired weapons and anti-aircraft machine guns - came into northern Syria via the Turkish province of Hatay in the past 24 hours, and was already being handed out, the sources added.

One rebel officer told Reuters the flow of arms bound for rebels had increased since opposition groups accused the government of launching deadly chemical weapons attacks in Damascus on Wednesday.

Read: US and UK warning over Syria

Iran has warned the United States against crossing the "red line" on Syria, saying it would have "severe consequences", according to the Fars news agency.

Watch: US says 'all options being examined' on Syria

Massoud Jazayeri, deputy chief of staff of Iran's armed forces is quoted as saying:

More: ITV News obtains graphic footage of alleged chemical attack in Syria

Prime Minister David Cameron and US president Obama have threatened a "serious response" against Syria, should evidence of a chemical weapons attack emerge.

Watch: Time running out to gather evidence of 'gas attack'

The warning comes as humanitarian organisation MSF said they have treated about 3,600 patients in Syria with "neurotoxic symptoms," in the hospitals they support within the country.

Watch: MSF 'almost certain' neurotoxic agent used in Syria

US defence secretary Chuck Hagel told a press conference yesterday that the US military is ready to exercise "all options," should Obama choose military action, as Jacob Greaves reports.

Warning: This report contains graphic images

More: First independent images of chemical attack in Syria emerge

The US military is ready to exercise all options on Syria, should President Obama choose military action, US Defence Secretary Chuck Hagel told a conference today.