A Cairo court confirmed death sentences for Muslim Brotherhood leader Mohamed Badie and 11 other defendants on Saturday, and a US-Egyptian citizen was jailed for life over Islamist protest violence.
Judge Mohamed Nagy Shehata also sentenced to death two Islamists who have fled the country, and he handed life terms to 23 detained defendants.
The defendants were accused of plotting unrest from their headquarters in a sprawling Cairo protest camp in the months after the military overthrew Islamist president Mohamed Morsi in July 2013.
Among those sentenced to life in prison was Mohamed Soltan, a US-Egyptian citizen who is on hunger strike.
His father Salah Soltan was among the 11 detainees sentenced to death.
Soltan's family called for Mohamed's immediate release in a statement after the verdict, charging that there was no evidence against him.
The US embassy, in a statement, said it was "gravely concerned" about Mohamed Soltan and would "continue to monitor his case closely and to provide him with all possible support."
The rulings can be appealed before the Court of Cassation, which has overturned dozens of other death sentences, including against Badie.
So far Egypt has executed one Islamist sentenced to death after Morsi's overthrow, following his conviction of involvement in the murder of a youth during violent protests in July 2013.
Shehata, who has sentenced dozens of Islamists to death in other cases, read out a Koranic verse that stipulates amputation and crucifixion for outlaws, before rendering his verdict on Saturday.
At a previous session, he had sought the opinion of the country's mufti, the Islamic legal authority, on the death sentences.
The mufti has an advisory role under Egyptian law.
Signup to our newsletter and follow us on Facebook and Twitter!
Known as the "Rabaa Operations Room" case, the prosecution accused the defendants of organising months of unrest and protests against the ouster of Morsi, a senior Brotherhood figure himself now on trial.
- Rabaa protest camp -
The Rabaa al-Adawiya protest camp in Cairo was dispersed by police on August 14, 2013 in a 12-hour operation that left hundreds of protesters and about 10 policemen dead.
Mohamed Soltan was shot in the arm during the dispersal, and he was arrested days later as police hunted down Islamist activists who had fled the protest camp.
Police moved in to disperse the camp after weeks of failed European and US-brokered negotiations with the Brotherhood, who publicly insisted on Morsi's return.
The Islamist was the country's first freely elected president and he ruled only for a year before the army toppled him, spurred by massive protests demanding his resignation.
President Abdel Fattah al-Sisi, the former army chief who toppled Morsi and then won an election, has pledged to eradicate the Brotherhood.
The government has blacklisted the movement as a terrorist organisation amid a spike in militant attacks that have killed dozens of policemen and soldiers.
The deadliest attacks have been claimed by jihadists in the Sinai Peninsula and in Cairo, and the Brotherhood insists it is committed to non-violence.
But decapitated and driven underground, the Islamist movement is believed to have radicalised with members adopting militant tactics against policemen.