BEIRUT — Emergency workers searched deep in the Mediterranean on Wednesday for the black boxes from a doomed Ethiopian Airlines jet as weather experts said that lightning had struck in the plane's path around the time of the deadly crash.

The plane went down in flames early Monday just minutes after takeoff from Beirut in a fierce thunderstorm. All 90 people on board were feared dead.

"It was not your average, run of the mill thunderstorm," AccuWeather.com meteorologist Jason Nicholls told The Associated Press on Wednesday. Using a network of lightning detection systems, Accuweather detected there was a lightning strike in the plane's path around the time of the crash, he said.

The black box and flight data recorder are critical to determining the cause of the crash.

Emergency workers will expand their search radius for the wreckage of an Ethiopian Airlines jet if they do not find the black boxes Wednesday, an army official said.

Searchers have fanned out for 30 kilometres along Beirut's coast, and about 5 miles (8 kilometres) out to sea, said the official, who spoke on condition of anonymity because he is not authorized to speak publicly.

The army official said the sea was 1,000 metres deep in some areas being searched and international search teams were using divers and sonar. He said emergency crews were bringing the pieces of the plane they have found to a military base.

Rescue teams have recovered some bodies and pieces of the plane, but hope for finding any survivors has faded.

Ethiopian Foreign Minister Seyoum Mesfin cautioned against speculating about the cause of the crash, saying investigators still need to find the black boxes.

"It is not helpful, particularly to those who had their loved ones on board," he told journalists in Beirut.

In Addis Ababa, Prime Minister Meles Zenawi said 26 bodies have been found so far, five of them Ethiopians, according to the state-run news agency.

On Tuesday, Lebanon's transportation minister said the pilot made a "fast and strange turn" minutes after takeoff. He, too, said it was far too early to know the cause of the crash.

Transportation Minister Ghazi Aridi revealed that the plane flew in the opposite direction from the path recommended by the control tower after taking off in stormy weather.

He said the pilot initially followed the tower's guidance, but then abruptly changed course and went in the opposite direction.

"They asked him to correct his path but he did a very fast and strange turn before disappearing completely from the radar," Aridi told The Associated Press.

"Nobody is saying the pilot is to blame for not heeding orders," Aridi said, adding: "There could have been many reasons for what happened. ... Only the black box can tell."