A missile struck a helipad inside the US Embassy in Baghdad, two security officials said.The projectile landed within the embassy's boundaries after the Green Zone, the heavily fortified district in central Baghdad that houses Iraqi government institutions and foreign embassies, added the security officials, who spoke on the condition of anonymity as they are not authorised to speak with the press.Video obtained by The Associated Press showed smoke billowing from inside the compound.READ MORE: Will the pumps run dry?