Egypt's president pardoned Canadian Al-Jazeera journalist Mohamed Fahmy and his colleague Baher Mohamed among 100 prisoners on Wednesday, after his government faced criticism for jailing opponents.

Those pardoned by President Abdel Fattah al-Sisi also included women activists Sana Seif and Yara Sallam, his office said, in a gesture on the eve of a major Muslim holiday.

The journalists Fahmy and Mohamed were sentenced in a retrial to three years in August for allegedly fabricating "false" news in support of the Muslim Brotherhood movement, which the army removed from power in 2013 and outlawed.

Australian reporter Peter Greste was also convicted, although he had been deported by presidential decree. It was not immediately clear if he was included in the pardon.

Their detention and trial sparked global criticism towards Sisi, who has said he wished the journalists had been deported from the outset rather than put on trial.

After their sentencing last month, Egypt summoned the British ambassador to Cairo for criticising the ruling.

The United States and the United Nations had led calls for the journalists' release.

"I am so happy. Mohamed is so happy," Fahmy's fiance Marwa Omran told AFP.

Their arrest in December 2013 came at a time of heightened unrest and a deadly crackdown on the Muslim Brotherhood following Islamist president Mohamed Morsi's overthrow by the military.

At the time, Qatar, which owns Al-Jazeera, had been supportive of the Islamists.

Fahmy had dropped his Egyptian citizenship to qualify for deportation like Greste.

His fiance said that, after his release, "he wants to pursue getting his nationality back".

Free in 24 hours

He and the others were scheduled to be released in the next 24 hours, said Omran.

The pardons came on the eve of the Muslim holiday of Eid al-Adha, when prisoner releases often take place in Muslim countries.

They appeared aimed at activists for the most part, with the presidency saying the cases involved violations of a protest law and "assaulting police officers," in addition to some pardons on health grounds.

Sisi has faced mounting calls to release activists such as Seif and Sallam, a human rights worker detained after a small protest outside the presidential palace in 2014.

The two women were charged with holding an illegal protest, under a law that bans all but police-sanctioned demonstrations, and sentenced to three years in jail.

No official list was immediately issued of those pardoned on Wednesday, leaving it unclear whether other secular activists such as Alaa Abdel Fattah and Ahmed Maher were included.

It was also not known if the pardon covered Mahmoud Abu Zeid, a photographer arrested in August 2013 as hundreds of Islamist protesters were killed in clashes with police clearing two Cairo sit-ins.

Thousands of Islamists, including Morsi, have been arrested since his overthrow, and scores sentenced to death.

But the crackdown on the Islamists has also extended to secular leaning activists who had supported Morsi's overthrow after his divisive year in power.

Sisi, the former army chief who was elected president in 2014, remains popular with many Egyptians an end to unrest in the wake of the country's 2011 revolution that toppled longtime strongman Hosni Mubarak.

He has vowed to steer clear of court cases out of respect for the judiciary's independence.