Egypt is now the fourth country to declare Hamas as a "terrorist" organisation, following Israel, the US and Canada.
An Egyptian court has branded Hamas a "terrorist" organisation, weeks after the Palestinian movement's armed wing was given the same designation.
A judicial source told AFP news agency that the court issued the verdict on Saturday, a ruling seen as keeping with a systematic crackdown on Islamist groups by President Abdel Fattah el-Sisi.
The verdict resulted from two separate private suits filed by two lawyers against the de facto rulers of the Gaza Strip.
Hamas spokesperson Sami Abu Zuhri denounced the court ruling. "The Egyptian court decision...is shocking, critical and targets the Palestinian people and Palestinian resistance forces," he said.
Palestinians in the Jabaliya refugee camp in northern Gaza held a demonstration on Saturday in protest of the Egyptian court's decision.
Mustafa Barghouti, an independent senior Palestinian official, told Al Jazeera that the verdict "is a very unwise decision" that carries political complications.
"Hamas is part of the Palestinian national unity movement, and this decision is not useful," Barghouti said.
String of attacks
Saturday's ruling comes just days after Egypt adopted a new anti-terrorism law allowing the authorities to close the premises of any declared "terrorist" organisation, and to freeze its assets as well as those of its members.
The relationship between Egypt's authorities and Hamas has soured since the ouster of the Muslim Brotherhood's Mohamed Morsi in July 2013.
Hamas is an offshoot of Egypt's Muslim Brotherhood, which Egypt also banned after the military coup in 2013.
Since then, Egyptian authorities have accused Hamas of aiding armed groups, who have waged a string of deadly attacks on security forces in Egypt's Sinai Peninsula.
In January, an Egyptian court also declared Hamas' armed wing al-Qassam Brigades a "terrorist" group.
The case was based on allegations that al-Qassam staged attacks to support the Muslim Brotherhood, and carried out deadly operations in the Sinai Peninsula in October 2014, allegations that the group denied.
Armed groups in Sinai have killed scores of policemen and soldiers since Morsi's overthrow, vowing revenge for a crackdown on his supporters that has left more than 1,400 people dead. Most of the attacks however have been claimed by the armed group Ansar Beit al-Maqdis, which has pledged its allegiance to the Islamic State of Iraq and the Levant.
Source: Al Jazeera and agencies