An Egyptian criminal court on Monday sentenced 11 defendants to life in prison on charges of joining the Islamic State extremist group in Syria and Iraq.
The Giza Criminal Court also sentenced two other defendants to 15 years in prison and another to three years in the same case.
All verdicts can be appealed.
The charges against the defendants include receiving training to carry out hostile acts in the country, plotting attacks on police and military forces and seeking to forcibly topple the government.
Egypt has been battling an Islamist insurgency in northern Sinai since the 2011 uprising that toppled long-time autocrat Hosny Mubarak.
The attacks have intensified after the military in 2013 deposed Mohammed Morsi, the first democratically elected but divisive Islamist president of Egypt.
After his ouster, Morsi was detained and tried in several cases.
He died in mid-June at the age of 67 after suddenly collapsing inside a courtroom in Cairo.