Updated

Queen Elizabeth II and her children visited her husband, Prince Philip, in hospital Saturday, where he is recovering from heart surgery.

Philip, 90, was taken to the hospital from the queen's Sandringham estate in Norfolk late Friday after experiencing chest pains. He had a coronary stent put in after tests found a blocked artery was to blame, though the palace has refused to say if he suffered a heart attack.

Elizabeth was flown in by helicopter and arrived at Papworth Hospital, some 70 miles (113 kilometers) from London, shortly after 11 a.m. with three of her children -- Princess Anne, Prince Edward and Prince Andrew. The palace said Prince Charles and his wife, Camilla, arrived at the hospital 45 minutes later by car and that no further family visits are expected.

Philip is "in good spirits but he is eager to leave," Buckingham Palace said. After spending 45 minutes with Philip, the royals traveled back to Sandringham by helicopter, it added.

Doctors said Philip could have suffered a heart attack, but without more information it was impossible to know for sure.

Coronary stenting is standard procedure both to fend off a heart attack or save a patient already in the midst of one, said Dr. Allan Schwartz, chief of cardiology at New York-Presbyterian, Columbia University Medical Center.

Philip has been known to enjoy good health throughout his life and rarely misses royal engagements. Upon his 90th birthday in June, he announced plans to cut back his official duties.

Britain's Prime Minister David Cameron offered his support to Philip.

"The Prime Minister has been kept informed of the situation and wishes the Duke of Edinburgh a very speedy recovery," Cameron's office said.

Doctors say that some patients can leave the hospital a day after a similar medical procedure, but the palace said it does not know when Philip will be released. It said the prince remains "under observation" and that he is having a "short stay" in the hospital.

It is unclear if Philip will be able to join the royal family for the traditional Christmas celebrations at Sandringham, the queen's sprawling rural estate in Norfolk where the royal family gathers for the festivities. Philip had been there since Monday.

The palace said Elizabeth and the royal family will attend church as usual on Sunday.

Another key part of the royal family's Christmas celebrations is the queen's annual message to the nation, which this year will focus on family and community.

The queen has made a prerecorded Christmas broadcast on radio since 1952 and on television since 1957. She writes the speeches herself, and the broadcasts mark the rare occasion on which the queen voices her own opinion without government consultation.