Some 140 detainees, who were imprisoned recently, many for breaching the protest law, are expected to be released within days, a member of Egypt's National Council for  Human Rights Council (NCHR) said on Tuesday.

The list represents a first batch of prisoners to be set free, human rights lawyer Hafez Abu Seada told Ahram Online, after Egypt's president promised on Sunday to release "unjustly imprisoned Egyptians."

Abu Saeda, who is also the head of the Egyptian Organization for Human Rights (EOHR), said that three lists of detainees had been presented to President Abdel-Fattah El-Sisi in recent months for him to consider a presidential pardon to release them.

One list, presented by the NHCR, included 600 names, while another, drafted by the EOHR, included 200 names. A third, submitted by young journalists, listed 300 people.

Earlier this year, before the fourth anniversary of the 25 January revolution, the president issued a decree to pardon hundreds of prisoners, including students.

Egyptian human rights groups and parties had their hopes dashed, however, as the released prisoners did not include most of the names in the submitted lists.

At the time, eligible candidates for presidential pardon included prisoners with a life sentence who would have served 15 years by 25 January 2015.

Also eligible were those with a prison sentence of at least six months, half of which would have been served by 25 January 2015.

On Sunday, El-Sisi conceded the existence of a number of unjustly detained Egyptians and promised that the government would start releasing them.

He did not make it clear according to which criteria they would be released.

A protest law, passed in 2013, criminalises unauthorised protests, and sets heavy jail terms and fines for those who breach the law.

Thousands of protesters, mostly Islamists but also hundreds of non-Islamist supporters of the 25 January revolution, have been arrested in accordance to the protest law, following the ouster of president Mohamed Morsi in July 2013.

Local and international human rights groups have criticised the law.

On Monday, leading leftist activist Alaa Abdel-Fattah received five years in jail for taking part in an unauthorised demonstration in 2013, among other charges.

A second defendant received the same sentence as Abdel-Fattah, while 18 others received a three-year jail term.

The court upheld the original in-absentia 15-years jail sentence against four other defendants.

All defendants were charged with rioting, participating in an illegal protest, disrupting the lives of citizens and exposing them to danger, attacking an employee while on duty and thuggery.