Few Egyptians expected a day when Hosni Mubarak would be under arrest. Now they get to see at least 15 more days of it, the prosecutor general said Friday, and investigators are questioning an ever-widening slice of the former president’s inner circle.

But as the inquiry broadens, Mubarak, who is being confined to a pyramid-shaped hospital in the resort town of Sharm el-Sheikh, is winning broader sympathy, too.

While many Egyptians welcomed the prosecutor’s decision — and said they hoped it was the prelude to a more permanent detention — a growing number of people are watching the expanding investigation with discomfort, saying that Mubarak, who turns 83 next month, should be left in quiet retirement.

“We can’t put an old man like that on trial,” said Fatheya Awwad, 50, a dressmaker attending a pro-Mubarak rally that drew about 200 people along the Nile on Friday. “He kept us safe for 30 years.”

Mubarak and his sons, Gamal and Alaa, were detained earlier this month for questioning, the former president for his possible role in the deaths of protesters in January and February and all three for possible corruption during their decades in power.

Gamal and Alaa Mubarak are in Tora prison on the outskirts of Cairo, along with several former cabinet ministers and other prominent members of Mubarak’s National Democratic Party. Hosni Mubarak was questioned for 15 minutes earlier this month, then rushed to the hospital after having what variously has been described as chest pain, a minor heart attack or palpitations. He has been in the hospital since.

The extension of the detention period, which was reported in the state-owned al-Ahram newspaper, means that Mubarak will remain in custody until at least May 13 and will celebrate his 83rd birthday on May 4 while detained.

More and more members of the Mubarak family are being investigated. Mubarak’s wife, Suzanne, has been questioned about allegations that she profited from secret bank accounts connected to the Library of Alexandria. Gamal and Alaa Mubarak’s wives will be questioned Tuesday on allegations that they improperly accumulated wealth, al-Ahram reported.

Prosecutors are also considering transferring the former president to Tora prison or to a military hospital close to Cairo. Mubarak has asked the ruling military council to allow him to stay in the hospital in Sharm el-Sheikh, al-Ahram reported.

Mubarak is not being detained under the much-hated emergency law that allows the government to detain people indefinitely without charges. But many of his supporters echo the law’s detractors, saying that he should be charged with a crime if he is going to be held.

“I’m only calling for a fair trial,” said Mohammed Hussein, 33, a quality-control engineer who was at the pro-Mubarak rally Friday. “I am against the trial of public opinion.”

Hussein said that he held no special sympathy for Gamal and Alaa Mubarak but that their father should be treated differently.

“Mubarak is a symbol who shouldn’t be humiliated,” he said.

Still, many here welcomed the detention.

“The Mubarak trial is 30 years late,” said Hend Abel Hamed, 30, who works at a government ministry and was eating Friday at a cafe just off Tahrir Square, the center of the protests that toppled the president. “He imposed a repressive regime from the first days.”

Special correspondent Haitham Tabei contributed to this report.