KUALA LUMPUR, Malaysia — Malaysian authorities defended their handling of the hunt for the missing Boeing 777 on Wednesday even as they acknowledging they were unsure which direction the plane was headed when it disappeared, highlighting the massive task facing an international search mission now in its fifth day.

The mystery over the plane’s whereabouts has been confounded by confusing and occasionally conflicting statements by Malaysian officials, adding to the anguish of relatives of the 239 people on board the flight — two thirds of them Chinese.

“There’s too much information and confusion right now. It is very hard for us to decide whether a given piece of information is accurate,” Chinese Foreign Ministry spokesman Qin Gang told reporters in Beijing.

Malaysian Defense Minister Hishammuddin Hussein described the multinational search for the missing plane as an unprecedented and complicated effort and defended his country’s efforts. Some 43 ships and 39 aircraft from at least eight nations were scouring an area of 35,800 square miles.

“It’s not something that is easy. We are looking at so many vessels and aircraft, so many countries to coordinate, and a vast area for us to search,” he said. “But we will never give up. This we owe to the families” of those on board.

Malaysia Airlines flight 370 took off from Kuala Lumpur for Beijing early Saturday morning and fell off civilian radar screens at 1:30 a.m. about 35,000 feet above the Gulf of Thailand between Malaysia and southern Vietnam. It sent no distress signals or any indication it was experiencing any problems.

Malaysian authorities have since said that say air defense radar picked up traces of what might have been the plane turning back and flying until it reached the Strait of Malacca, a busy shipping lane west of the narrow nation some 250 miles from the plane’s last known coordinates.

Military and government officials said American experts, and the manufacturer of the radar systems, were examining that data to confirm it showed the Boeing 777. Until then, they said the search would continue on both sides of the country, with an equal focus.

Dozens of ships and planes searching waters have failed to turn up anything, prompting officials to expand the hunt. Malaysia asked India to join the search for the missing jet in waters near the Andaman Sea — far to the northwest of its last reported position.

“As of today, we have not found anything, but we are extending (the search) further,” Hishammuddin said.

Air force chief Gen. Rodzali Daud said air defense radar showed an unidentified object at 2:15 a.m. about 200 miles northwest of Penang.

“I am not saying it’s flight MH370. We are still corroborating this. It was an unidentifiable plot,” he said.

It’s unlikely the plane would have flown across Malaysia without being detected by civilian radar unless its electrical systems, including transponders allowing it to be identified by radar, were either knocked out or turned off.