Malaysia said Tuesday that it has narrowed the search for a downed jetliner to an area the size of Texas and Oklahoma in the southern Indian Ocean, while Australia said improved weather would allow the hunt for possible debris from the plane to resume.

The comments from Defense Minister Hishammuddin Hussein came a day after the country’s prime minister announced that a new analysis of satellite data confirmed the plane had crashed in a remote part of the southern Indian Ocean, killing all 239 aboard.

But the searchers will face a daunting task of combing a vast expanse of choppy seas for suspected remnants of the aircraft sighted earlier.

“We’re not searching for a needle in a haystack — we’re still trying to define where the haystack is,” Australia’s deputy defense chief, Air Marshal Mark Binskin, told reporters at a military base in Perth, Australia, as idled planes stood behind him.

There had been two corridors — based on rough satellite data — for the search. Hishammuddin said operations had been halted in the northern corridor that swept up from Malaysia toward Central Asia, as well as in the northern section of the southern corridor that arches down from Malaysia toward Antarctica.

That still leaves a large area of 1.6 million square kilometers (622,000 square miles), but just 20 percent of the area that was previously being searched.

In remarks to the Malaysian Parliament on Tuesday, Prime Minister Najib Razak cautioned that the search will take a long time and “we will have to face unexpected and extraordinary challenges.”

Late Monday, Najib announced that the Boeing 777 had gone down in the sea with no survivors. That’s all that investigators and the Malaysian government have been able to say with certainty about Flight 370’s fate since it disappeared on March 8 shortly after taking off from Kuala Lumpur for Beijing.

Left unanswered are many troubling questions about why it was so far off course. Experts piecing together radar and satellite data believe the plane back-tracked over Malaysia and then traveled in the opposite direction to the Indian Ocean.

Investigators will be looking at various possibilities including mechanical or electrical failure, hijacking, sabotage, terrorism or issues related to the mental health of the pilots or someone else on board.

“We do not know why. We do not know how. We do not know how the terrible tragedy happened,” the airline’s chief executive, Ahmad Jauhari Yahya, told reporters.

Najib’s announcement set off a storm of anguish and anger among the families of the passengers and crew — two-thirds of them Chinese.

Nearly 100 relatives and their supporters marched to the Malaysian Embassy in Beijing, where they threw plastic water bottles, tried to rush the gate and chanted, “Liars!”

Many wore white T-shirts that read “Let’s pray for MH370” as they held banners and shouted, “Tell the truth! Return our relatives!”

President Xi Jinping ordered a special envoy, Vice Foreign Minister Zhang Yesui, to Kuala Lumpur to deal with the case, and Deputy Foreign Minister Xie Hangsheng told Malaysia’s ambassador that China wanted to know exactly what led Najib to announce that the plane had been lost, a statement on the ministry’s website said.

Malaysia Airlines Chairman Mohammed Nor Mohammed Yusof said at a news conference Tuesday that it may take time for further answers to become clear.

(AP)