Evidence of the use of chemical weapons has been discovered in a soil sample smuggled out of Syria, The Times of London reported on Saturday. The report quoted anonymous British defense sources who said that "some kind of chemical weapon" was used in Syria but they could not tell whether the chemicals were used by Syrian President Bashar Assad's forces or by the rebels. The finding was established by the British Ministry of Defense's chemical and biological research establishment at Porton Down in in Wiltshire. The sources ruled out that the chemical traces found in the soil were from substances used to control riots with one saying, “There have been some reports that it was just a strong riot-control agent but this is not the case — it’s something else, although it can’t definitively be said to be sarin nerve agent.” The soil sample was smuggled out of Syria in a secret British operation that was revealed by a report in The Times in March. Western diplomats said evidence of chemical weapons use were found, but failed to specify. "There are several examples where we are quite sure that shells with chemicals have been used in a very sporadic way," one such diplomat was quoted as saying.Another diplomat said that "quite convincing" evidence was sent to UN Secretary-General Ban Ki-moon to back the accusations made against forces loyal to Assad. However, The Times report quoted a source who said the soil analyzed by Porton Down “did not point the finger definitively at the Assad regime.” UN Secretary-General Ban Ki-moon said on Monday that a team to investigate claims of chemical weapons use in Syria was ready to deploy within 24 hours and urged the Syrian government to give the go-ahead so work could begin.Ban, who met the head of the global chemical weapons monitoring body in The Hague, said an advance team had been sent to Cyprus. "We are ready, it is a matter of time," he said. The full team will consist of 15 experts, including inspectors, medical experts and chemists. The Syrian government is only willing to allow the UN to investigate what it claims was a rebel chemical attack near Aleppo last month. The opposition has blamed Assad's forces for that strike and also wants the UN team to look into other alleged chemical attacks by the government. According to the the Saturday report in The Times, the soil sample was believed to be taken from an area near Damascus. US President Barack Obama warned Assad in two previous occasions against using chemical weapons against Syrian opposition forces, saying there would be consequences if he were to do so."I want to make it absolutely clear to Assad and those under his command: The world is watching," Obama said in a speech to a gathering of biological, chemical and nuclear weapons proliferation experts in March."The use of chemical weapons is and would be totally unacceptable and if you make the tragic mistake of using these weapons, there will be consequences and you will be held accountable," Obama said. Reuters contributed to this report.