The pilot of doomed Ethiopian plane ET 302 tried to save his passengers and asked to turn the flight around just before losing contact, it has emerged.

The Boeing 737 MAX 8, carrying 157 people, crashed shortly after take-off from the Ethiopian capital overnight, with investigators at a loss to explain the tragedy.

Ethiopian Airlines CEO Tewolde Gebremariam said the pilot was given clearance to turn back after reporting a problem with the plane and sending out a distress call.

A recovery mission is taking place as aide workers look for bodies in the wreckage (AAP)

The crash site where the Ethiopian Airlines Boeing jet came down. (Getty)

The plane was only registered in November and is the second fatal disaster involving a Boeing 737 MAX 8 aircraft in just five months.

Last October a Lion Air flight – also a MAX 8 – crashed just 12 minutes after take-off from Jakarta, killing all 189 people onboard.

Boeing is sending air crash experts to Ethiopia. (AAP/Supplied)

Wreckage at the site. (EPA/AAP)

The Ethiopian plane crashed just six minutes after departure, slamming into the ground at Hejere near Bishoftu, or Debre Zeit, some 60 kilometres outside Addis Ababa, at 8:44 am.

FlightTracker 24 said it showed unstable vertical speed.

Revealing how he was devastated at the loss of the plane, crew and passengers, Mr Gebremariam said the experienced pilot had an “excellent flying record” and the plane was new with routine maintenance not revealing any issues.

“It is a brand-new aeroplane with no technical remarks, flown by a senior pilot and there is no cause that we can attribute at this time,” he said.

“Ethiopian Airlines is one of the safest airlines in the world. At this stage we cannot rule out anything.”

The airline boss said there were no defects prior to the flight and said it was hard to see any parallels with the Lion Air crash.

The jet’s last maintenance was on February 4, and it had flown just 1200 hours.

Undated handout photo issued by the Association of Arctic Expedition Cruise Operators (AECO) of Sarah Auffret, who has been identified bas a victim of the Ethiopian Airlines flight ET302, which crashed shortly after take off from Addis Ababa. (PA/AAP)

SECOND TRAGEDY HITS

Investigators stress it remains too early to know whether the Ethiopia crash was caused by the same issues that doomed the Indonesian flight.

Indonesian investigators have not determined a cause for the October crash, but days after the accident Boeing sent a notice to airlines that faulty information from a sensor could cause the plane to automatically point the nose down.

The Lion Air cockpit data recorder showed that the jet’s airspeed indicator had malfunctioned on its last four flights, though the airline initially said problems had been fixed.

The grisly task of searching for the dead passengers and crew has started. (AAP/Supplied)

The crash is a serious blow to state-owned Ethiopian Airlines, which has expanded to become the continent’s largest and best-managed carrier and turned Addis Ababa into the gateway to Africa.

The crash is likely to renew questions about the 737 Max, the newest version of Boeing’s popular single-aisle airliner, which was first introduced in 1967 and has become the world’s most common passenger jet.

Aviation analysts say they are anxiously awaiting the results of the Indonesian airline’s investigation, suggesting the company’s future business could be affected if any parallels are found.

Family members of the victims involved in a plane crash react after hearing there were no survivors onboard. (AP/AAP)

“If this has any relationship at all with Lion Air incident, it’s a pretty good bet that the [Federal Aviation Administration] will move to have all 737 MAX aircraft inspected immediately,” said Mike Boyd, an aviation analyst with US-based Boyd Group International.

If the results of such an inspection turn up significant design flaws in the 737 MAX, it could lead the planes to be grounded worldwide, he said.

BOEING 'READY TO SUPPORT'

In a statement addressing the crash in Ethiopia, Boeing said it has a technical team prepared to provide assistance at the direction of the US National Transportation Safety Board.

“Boeing is deeply saddened to learn of the passengers and crew on Ethiopian Airlines Flight 302, a 737 MAX 8 airplane,” it said in a statement.

“We extend our heartfelt sympathies to the families and loved ones of the passengers and crew on board and stand ready to support the Ethiopian Airlines team.”

There are believed to be no Australians among the 157 dead.

Among the fatalities there are at least 35 nationalities.

Thirty two are from Kenya, 18 from Canada and eight from the US and Italy. There are also seven each from Britain and France.

The United Nations migration agency says the UN and its agencies on Monday will fly flags at half-staff after early indications show 19 employees of UN-affiliated organisations died in the Ethiopian Airlines crash.

THE VICTIMS

The list reflected a broad range of backgrounds, with passengers also from China (8), Italy (8), Egypt (6), Germany (5), India (4), Slovakia (4), Austria (3), Sweden (3) and Russia (3) among others.

Some of those aboard were thought to be travelling to a major United Nations environmental meeting scheduled to start today in Nairobi.

Briton Joanna Toole, 36, a UN fisheries expert was among the UK citizens killed in the Ethiopia air crash. (OceanCare). (Nine/Supplied)

Irish citizen Michael Ryan was one of the UN workers killed in the crash. (AAP)

They included Sarah Auffret, who according to her employers the Association of Arctic Expedition Cruise Operators, was due to discuss tackling plastic pollution in the seas at the assembly.

Other confirmed victims include Briton Joanna Toole, a fisheries expert, and Irishman Michael Ryan, a UN worker.

A statement says the organisations include World Bank, International Telecommunications Union, the UN Environment Program and others.

The Russian Embassy in Ethiopia says the airline has identified the three Russians on board as Yekaterina Polyakova, Alexander Polyakov and Sergei Vyalikov. News reports identify the first two as husband and wife. State news agency RIA-Novosibirsk cites a consular official in Nairobi as saying all three were tourists.

Family and friends of those on board are looking for answers (AAP)

Serbia’s foreign ministry confirms that a citizen was among those killed but gives no details. Local media identify the man as 54-year-old Djordje Vdovic. The Vecernje Novosti daily reports that he worked at the World Food Program.

The Paris prosecutor’s office has opened an investigation into the Ethiopian Airlines crash because there are French citizen.

FAMILIES WAIT

Worried families gathered at the flight's destination, the airport in Nairobi, the capital of neighbouring Kenya.

Some relatives were frustrated by the lack of information about loved ones (AAP)

Agnes Muilu said he came to pick up his brother. "I just pray that he is safe or he was not on it," he said.

Relatives were frustrated by the lack of information about loved ones.

"Why are they taking us round and round. It is all over the news that the plane crashed," said Edwin Ong'undi, who was waiting for his sister.

"All we are asking for is information to know about their fate."

Others were holding out hope their loved ones didn't make it onto the flight (AAP)

As sunset approached at the crash site, searchers and a bulldozer picked through the wreckage of the plane, which shattered into small pieces.

Photos from the scene showed multi-coloured pieces of the jet strewn across freshly churned earth.

Ehiopian Airlines CEO made his way out to the crash site to survey the wreckage (AAP)

Red Cross teams and others were searching a large area for human remains.

In one photo, teams could be seen loading black plastic bags into trucks.

The airline published a photo showing its CEO standing in the wreckage.

State-owned Ethiopian Airlines is widely considered the best-managed airline in Africa and calls itself Africa's largest carrier.

It has ambitions of becoming the gateway to the continent and is known as an early buyer of new aircraft.

Pieces of the colourful plane were spread out across the field (AAP)

The last deadly crash of an Ethiopian Airlines passenger flight was in 2010, when a plane went down minutes after takeoff from Beirut, killing all 90 people on board.

Sunday's crash comes as the country's reformist prime minister, Abiy Ahmed, has vowed to open up the airline and other sectors to foreign investment in a major transformation of the state-centered economy.

The plane was only six minutes into its journey to Nairobi when it crashed. (9news)

Ethiopian Airlines has been expanding assertively, recently opening a route to Moscow and in January inaugurating a new passenger terminal in Addis Ababa to triple capacity.

The Ethiopian prime minister's office have offered their condolences in wake of the incident.

"The Office of the PM, on behalf of the Government and people of Ethiopia, would like to express it's deepest condolences to the families of those that have lost their loved ones on Ethiopian Airlines Boeing 737."