SYDNEY: Technical troubles have hindered a resumption of the search for missing Malaysia Airlines Flight MH370 with a mini-sub lasting only two hours in the water before it had to be raised, the Joint Agency Coordination Center (JACC), which is organizing the search, said on Wednesday. Australian vessel Ocean Shield, carrying the US Navy Bluefin-21 submersible, arrived back in the southern Indian Ocean search zone on Tuesday following a port visit to Perth after the air and sea hunt was scaled back. The plan was for it to resume scouring the seabed where transmissions believed to have come from the plane’s black box flight recorders were heard last month. The Boeing 777 vanished on March 8 with 239 people on board after mysteriously diverting from its Kuala Lumpur-Beijing route. It is believed to have crashed far off Australia’s west coast.