Kuala Lumpur - Malaysia said on Sunday the number of countries involved in efforts to find a missing passenger jet had nearly doubled to 25 as it began a new push to find the plane across a vast arc of land and ocean.
"The number of countries involved in the search and rescue operation has increased from 14 to 25, which brings new challenges of co-ordination and diplomacy to the search effort," said Hishammuddin Hussein, Malaysia's defence and transport minister.
Malaysia had said on Saturday satellite data showed Malaysia Airlines Flight 370 could have flown anywhere from Kazakhstan to the southern Indian Ocean after disappearing from civilian radar on 8 March.
Hishammuddin told a press conference that Malaysia, which is co-ordinating the hunt, had briefed representatives from at least 22 countries today and requested their help in a search that has become increasingly daunting.
This includes potentially sensitive military and satellite data from the likes of the United States, China and France.
Asked if any search for an aircraft in such a vast area could be effective, Hishammuddin acknowledged the size of the task.
"It is our hope that parties that can be of assistance to us can come forward and help us to narrow the search to an area that is much more feasible," he said.
Malaysian police also said it was seeking background checks on all passengers from foreign counterparts and intelligence agencies as it ramps up investigations into who may have deliberately diverted the Boeing 777 from its original course to Beijing.
Police on Saturday searched the homes of both pilots and seized Captain Zaharie Ahmad Shah's self-assembled flight simulator.