Media playback is unsupported on your device Media caption Helen Thomas was a fixture at White House news conferences

Helen Thomas, a trailblazing journalist who covered the White House for nearly five decades, has died aged 92.

She died at her Washington apartment after a long illness, the Gridiron Club, Washington's historic press organisation, said.

Ms Thomas covered the administrations of 10 presidents and was known for asking difficult questions.

She was a fixture at White House news conferences and considered a pioneer for women in journalism.

Veteran NBC News correspondent Andrea Mitchell tweeted that Helen Thomas "made it possible for all of us who followed".

Questioning was 'torture'

Born to Lebanese immigrants in Kentucky in 1920, Helen Thomas found her calling while working for her student newspaper at school.

She started out as a copy girl for a small Washington newspaper before moving to the United Press (UPI) wire service with whom she covered the presidential campaign of John F Kennedy.

Following Kennedy's election, the huge demand for stories about First Lady Jacqueline Kennedy helped Ms Thomas secure her place within the White House press corps.

Over the next decade, she began to report harder news and became UPI's White House bureau chief in the 1970s - the first woman to hold the post.

From her seat in the middle of the front row of the briefing room, she would grill presidents and exasperate government spokespeople with her pointed, persistent questions.

Image caption A White House birthday treat for President Obama and Helen Thomas who share the same 4 August birthday, in 2009

One White House press secretary described her questioning as "torture" - and he was one of her fans, the Associated Press reports.

She was particularly tough on former President George W Bush and persistently challenged him over the war in Iraq, describing him to another reporter in 2003 as the "worst president ever".

"I have never covered the president in any way other than that he is ultimately responsible," she once said.

Ms Thomas was a pioneer for women in journalism, notching up a series of firsts during her career.

She became the first female president of the White House Correspondents Association (WHCA), the first female member of the Gridiron Club and the only female print journalist to travel with President Richard Nixon on his first trip to China.

As the senior news service correspondent at the White House, she was often the one who would end the news conference with the phrase "Thank you, Mr President".

Her career ended under a cloud in 2010 after she said in an interview that Israeli Jews should "get the hell out of Palestine" and "go home" to Germany, Poland and America.

She later said she deeply regretted the comments, saying "they do not reflect my heartfelt belief that peace will come to the Middle East only when all parties recognise the need for mutual respect and tolerance".

Her husband, Douglas Cornell, who was the Associated Press's chief White House correspondent, died in 1982.