Syrian government forces says they found materials including chemical weapons protection masks made in the US, and toxic chemical agent containers made in Saudi Arabia, when it raided a tunnel in the opposition stronghold of Jobar near Damascus on Saturday.A Syrian army officer told reporters that soldiers participating in the raid showed symptoms such as suffocation and dilated pupils in addition to vomiting and general fatigue. According to the army, symptoms appeared minutes after opposition militants detonated two explosive devices. The officer said chemical agents are still being analysed.The claims follow condemnation from countries such as the UK, France and the US of the Assad government after an alleged chemical weapons attack earlier in the week. Russia, has suggested that opposition militants could have been responsible for the attack.