KUALA LUMPUR  - Malaysian investigators are still waiting for some countries to send background checks on passengers who were on a missing Malaysia Airlines jetliner as they intensify inquiries into a suspected deliberate diversion of the plane, the country's police chief said on Sunday.



"There are still a few countries yet to respond to our requests," Khalid Abu Bakar told a news conference.



Police are also investigating airport ground staff and have intensified their checks on the two pilots, including examining a flight simulator seized from the captain's home, he said.



Investigators have stepped up their scrutiny of the 239 crew members and passengers of lost Malaysia Airlines Flight MH370.