BEIJING: China today welcomed India joining the multi-nation hunt for the missing Malaysian plane in what has become one of the biggest mysteries in aviation history.China, anxious for a quick breakthrough in the search for the Malaysia Airlines Boeing 777-200 with 154 of its nationals aboard, has so far confined its search to the South China Sea.Malaysia today widened its search into the Indian Ocean for the missing aircraft with 239 people aboard and sought radar data from its neighbours and India.Five Indians are also among the missing passengers. "Malaysia invited India for the search and rescue operations in the western part of the sea. We contacted the Indian side and confirmed it with them. We appreciate their efforts in search and rescue," Chinese Foreign Ministry spokesman Hong Lei told a media briefing here today answering questions whether Beijing is in touch with New Delhi.Hong said eight Chinese vessels, three aircraft and five helicopters all focused their efforts on the South China Sea based on data that the plane went missing over Vietnam on March 8.But as latest investigations pointed to new possibilities that the plane might have turned back and flown over the Malacca Straits and towards the Andaman Islands, Malaysia requested India to join search operations.India has deployed four warships along with six aircraft including the latest special surveillance P-8I plane and three helicopters under the 'Operation Searchlight'.As the theatre of operations shifted to the Indian Ocean, China has alerted its commercial ships plying in the Malacca Straits and the Andaman Sea to look out for debris from the missing plane.Asked whether China would now extend its search operations to the Andaman Sea, Hong said only the marine search and rescue centre can provide that information.While the scope of the search broadened, China continued to raise possibilities that the plane might be missing over the Gulf of Thailand located between Malaysia and Vietnam.Chinese researchers are reported to have detected a "seafloor event" resembling a tremor near the waters between Malaysia and Vietnam, an area suspected to be linked with the missing planes flightpath.The event occurred at about 2:55 am local time on Saturday, about one and a half hours after the plane's last definitive sighting on civilian radar, according to a research group on seismology and physics of the earth's interior under the University of Science and Technology of China "The seafloor event could have been caused by the plane possibly plunging into the sea," the research group said.