CAIRO (AFP) – Egypt's ailing ex-president Hosni Mubarak and his two sons have been placed in detention for 15 days as part of an inquiry into the use of force against protesters, prosecutors said on Wednesday.

A statement on the public prosecutor's Facebook page said chief prosecutor Abdel Maguid Mahmud authorised the detentions "as part of an inquiry into the use of force against protesters during the unrest in January and February."

Security officials said Mubarak was placed under detention in a hospital in the Red Sea resort of Sharm el-Sheikh, where he reportedly suffered a heart attack on Tuesday during questioning by prosecutors.

Police said Mubarak's two sons, Gamal and Alaa, arrived mid-morning at Tora prison complex in Cairo, home to other fallen officials and and some of the country's most notorious political prisoners.

They are accused of incitement to fire at demonstrators during a popular uprising that lasted from January 25 until February 11 when Mubarak reluctantly stepped down. Nearly 800 people died during the uprising.

Earlier, state television said the brothers were being detained for 15 days "for the needs of the inquiry" and had first been interrogated in Sharm el-Sheikh.

Videos posted on video-sharing site YouTube showed what appeared to be dozens of protesters outside a court complex where the Mubarak brothers were being questioned.

The crowd demanded the two be transported to prison in a police van, rather than a civilian car, and chanted: "The people demand the execution of the butcher." The authenticity of the footage could not be immediately verified nor the exact location of the courthouse determined.

The inquiry had been ordered on Sunday by Mahmud as part of a sweeping probe into corruption and abuse.

The Mubaraks were to be asked about allegations that they were "connected to the crimes of assault against protesters, leading to deaths and injuries", the official MENA news agency said.

Prosecutors had begun questioning Mubarak and his son Gamal on Tuesday, Justice Minister Abdel Aziz al-Guindi said, adding that the grilling over acquiring wealth illegally had not yet started "as that will be handled by the department of illicit gains."

State television reported that the 82-year-old former strongman had refused to eat or drink since he received news on Tuesday morning that he was to be questioned.

He was admitted by his bodyguards to the VIP wing of the Sharm el-Sheikh International Hospital, the report said, adding that the hospital was not accepting any patients except for emergency cases.

Police cars and ambulances surrounded the hospital, as well as a heavy military police presence, the television said.

The former president was dressed in a black and white track suit when he arrived at the hospital, a witness said.

Asked if Mubarak was in good health, hospital director Mohammed Fathallah replied: "Somewhat."

The state-owned daily Al-Ahram, citing sources in Sharm el-Sheikh, said on its website that Mubarak had gone to hospital "under the pretext of being unwell in order to avoid facing questioning."

The former president was also to be quizzed about allegations of graft, MENA added.

The prosecutor's summons came after the broadcast of an audio tape in which Mubarak defended his reputation and after weeks of mounting protests calling for him to be put on trial.

After he resigned, Mubarak and his family moved to a residence in Sharm el-Sheikh. Although he is subject to a travel ban, his relative freedom has been a thorn in the side of the military rulers.

Weekly protests demanding his trial have attracted tens of thousands and eventually led to a deadly clash with soldiers early Saturday after they tried to clear an overnight demonstration in Cairo's Tahrir Square.