SINGAPORE, Nov 16 (Reuters) - Southeast Asia"s Grab on Tuesday said it was experiencing a disruption to its services, with customers and drivers in Singapore, Indonesia and Malaysia complaining that they were having trouble using the app"s ride-hailing functions. "Some of our services are not accessible at the moment," Grab posted on its Facebook page.We are looking into this and we will update when the app is back up and running." Grab operates Southeast Asia"s most popular "super app", which provide ride-hailing, food and grocery delivery and payments in over 400 locations in eight countries. "We are experiencing some technical difficulties with the app and our engineers are working to recover the issue," Grab said.