The search for the missing Malaysian Airlines flight entered its fourth week Sunday with a growing group of planes and ships assisting in the effort, but as of the evening, there was still no confirmed sign of the passenger jet.

Aircraft scouring the Indian Ocean for signs of the plane, which vanished March 8, spotted a number of objects floating in the water Saturday. But determining whether the debris is related to the plane will have to wait until ships relocate the items and dredge them up to examine more closely.

On Saturday, observers on a Chinese plane spotted three suspicious floating items that were white, red and orange, according to Chinese state-run media and the Australian Maritime Safety Authority (AMSA). A marker was dropped so that authorities can try to relocate the items and confirm whether they are related to the plane that went mysteriously missing three weeks ago with 239 people on board. In another part of the ocean, searchers on an Australian plane also saw multiple objects in the water.

These sightings — in addition to a number of others from Friday — mark the first time the Australian-led search has seen promising items in the water that it can try to dredge up and examine.

Australian authorities said the search 1,150 miles west of Perth would resume on Sunday with 10 planes from Australia, Japan, China, Korea, the United States and Malaysia. There are now four ships in the search area, with six more due to arrive Sunday.

What happened to Flight 370?

But time is running out for the search team to locate the critical black box containing cockpit audio and flight data from Malaysia Airlines Flight 370.

The black box will emit signals for about 30 days, which gives the operation only about one more week to find it before it goes silent.

An Australian navy support vessel, which will tow U.S. Navy equipment listening for “pings” from the black box, is scheduled to depart Perth on Monday. But authorities still aren’t sure exactly where the plane’s flight ended.

The massive operation, one of the biggest in aviation history, shifted its focus Friday to a new section of the Indian Ocean 198,200 square miles in size.

Before then, the team spent more than a week looking much further south.

The search was moved 680 miles northeast after new analysis by investigators indicated that the aircraft was traveling faster than previously thought — and therefore ran out of fuel much sooner.

Ships being dispatched on Sunday are tasked with relocating the debris spotted by low-flying planes and looking at it more closely. This presents its own challenges, though. The searchers have sometimes seen debris but then struggled to relocate it, even within hours on the same day.

Forecasters expect weather to worsen on Sunday with light showers and low clouds, but search operations should be able to continue, according to AMSA.

On Sunday, 29 Chinese family members seeking answers from Malaysia’s government about what happened to their loved ones arrived in Kuala Lumpur, said Malaysia Airlines commercial director Hugh Dunleavy, according to the Associated Press. Two-thirds of the 227 passengers aboard Flight 370 were Chinese, and their relatives have expressed deep frustration with Malaysian authorities since the plane went missing.

Steve Wang, a representative of some of the Chinese families in Beijing, said the relatives are demanding more answers because they were not satisfied by the responses Malaysian government representatives gave them in China, AP reported.

“We have demanded that we meet with the prime minister and the transportation minister,” said Wang Chunjiang, whose younger brother, Wang Chunyong, was on Flight 370, according to AP. “We have questions that we would like to ask them in person.”

After a week when the search for the aircraft seemed to be making progress, with satellite images showing hundreds of objects floating in the water, the sudden shift of the search area to the northeast Friday essentially put the massive effort back at square one, experts said.

“We are starting on a blank page,” said Charitha Pattiaratchi, a professor of coastal oceanography at the University of Western Australia who studies this corner of the Indian Ocean. “We are in exactly the same situation we were in one week ago.”

The redirection of the search comes as a result of analysis of radar data collected as the plane traveled between the South China Sea and the Strait of Malacca, before contact was lost, AMSA said. The data show that the aircraft traveled faster than investigators thought, burned its fuel more quickly, and therefore traveled a shorter distance, according to the Australians.

The plane was supposed to fly north from Kuala Lumpur to Beijing but abruptly turned sharply westward an hour into the journey, then headed south with its various communications systems all offline, a sequence of events that investigators are trying to unravel.

The new area, though, is much closer to Perth, which will give planes more time to search, Australian officials said. And it moves the operation away from the turbulent part of the ocean known as the “Roaring Forties” to a region where Pattiaratchi said winds and currents are much calmer.