By Raushan Nurshayeva and Olga Dzyubenko
ASTANA/BISHKEK, March 17 (Reuters) - Central Asian neighbours Kazakhstan and Kyrgyzstan said on Monday no unidentified planes had crossed their air space on March 8, making it unlikely that a missing Malaysia Arlines jetliner could have been diverted along a northern route via Thailand.
Malaysia Airlines Flight MH370, which vanished with 239 people aboard, could hypothetically have reached Kazakhstan's air space, but it would have been detected there, the Kazakh Civil Aviation Committee said in a detailed statement sent to Reuters.
"Even if all on-board equipment is switched off, it is impossible to fly through in a silent mode," said the statement signed by the committee's deputy head Serik Mukhtybayev. "There are also military bodies monitoring the country's air space."
Malaysia Airlines planes had made nine regular flights to and from Europe over Kazakhstan's territory on March 8, Mukhtybayev said.
"Even hypothetically thinking, before reaching Kazakhstan's territory this plane would have had to fly over other countries along its route, where the flight zone is also closely monitored, so we would have received information from these countries," he added.
Malaysian Prime Minister Najib Razak on Monday called Almazbek Atambayev, the president of Kazakhstan's neighbour Kyrgyzstan, saying the route of the diverted plane could have crossed his country as well, Atambayev's press service said.
Razak asked the Kyrgyz leader to provide any information that could help the investigation, it added.
Kyrgyz civil aviation authorities ruled out any possibility of the airliner disappearing in or near Kyrgyzstan.
"No, this plane did not fly over Kyrgyzstan's territory," Dair Tokobayev, vice-president of Kyrgyzstan's main civilian airport Manas near the capital Bishkek, told Reuters.
"We have two military air bases - a U.S. and a Russian one - deployed in our country and equipped with pretty serious radar equipment, so they would have detected this plane."
Malaysia Airlines chief executive Ahmad Jauhari Yahya said on Monday that it was unclear exactly when one of the plane's automatic tracking systems had been disabled, appearing to contradict the weekend comments of government ministers.
Suspicions of hijacking or sabotage had hardened further when officials said on Sunday that the last radio message from the plane - an informal "all right, good night" - was spoken after the system, known as "ACARS", was shut down.