THE HAGUE, Netherlands (AP) — An investigation by the global chemical weapons watchdog has found “reasonable grounds to believe” that a Syrian air force military helicopter carried out a 2018 chemical attack. The probe by the Organization for the Prohibition of Chemical Weapons Investigation and Identification Team says the attack happened in the rebel-held northern Syrian town of Saraqeb on Feb. 4, 2018. It sickened 12 people, who all survived. The report released Monday marks the second time the investigation team has concluded that Syrian government armed forces likely were responsible for a gas attack. The government of President Bashar Assad has repeatedly denied using chemical weapons.