A court in Egypt has banned all activities by the Palestinian Islamist movement Hamas and ordered the seizure of its offices and assets.
A lawsuit filed by an Egyptian lawyer had demanded the move because of its links to the Muslim Brotherhood.
Egypt's interim government designated the Brotherhood a terrorist group in December, five months after President Mohammed Morsi was ousted by the army.
A Hamas spokesman, Sami Abu Zuhri, condemned the court ruling.
"The decision harms the image of Egypt and its role towards the Palestinian cause," he told Reuters news agency. "It reflects a form of standing against Palestinian resistance."
Egyptian Foreign Minister Nabil Fahmy told a news conference he was not aware of the ruling, but added: "Whoever threatens Egypt's security should understand that there will be consequences."
Senior Hamas officials, including deputy political leader Moussa Abu Marzouk, live in Cairo and may now be at risk of arrest.
Hamas, which governs the neighbouring Gaza Strip, was founded in the 1980s as an offshoot of the Brotherhood and the groups have close ties.
Since the overthrow of Mr Morsi, the authorities in Cairo have accused Hamas of interfering in Egyptian affairs and conspiring with jihadist militants based in the northern Sinai peninsula who have carried out attacks on government and security forces personnel, killing hundreds.
Mr Morsi and 35 others are on trial on charges including conspiring with foreign organisations - among them Hamas, Lebanon's Shia Hezbollah movement and Iran's Revolutionary Guards - to commit terrorist acts.
Prosecutors say the attacks by jihadists, whom Hamas's military wing has been accused of training, were intended to "bring back the deposed president and to bring Egypt back into the Muslim Brotherhood's grip".
Hamas says the allegations are fabricated and an attempt to demonise it.
The Palestinian group has also been accused of assisting Mr Morsi's escape from prison during the 2011 uprising against Hosni Mubarak. The ousted president and more than 100 others, including members of Hamas, are charged with murdering prison officers during the breakout.
Since July, the Egyptian authorities have also limited movement through the Rafah border crossing with the Gaza Strip and destroyed dozens of tunnels, which were dug under the border and used to smuggle food, fuel and weapons.