Lawyers for the men said the charges were "absolutely not true"
A group accused of plotting attacks in Egypt for the Lebanese Islamist group Hezbollah has gone on trial in Cairo.
The 22 defendants in court deny spying on ships in the Suez Canal and plotting attacks on holiday resorts popular with Israelis in Sinai.
At least one defendant said he had been tortured. Another four are on the run and being tried in their absence.
Hezbollah's leader has admitted one of the men was an agent for the movement but denied any plan to harm Egypt.
Sheikh Hassan Nasrallah said the Hezbollah member was tasked with smuggling weapons to Palestinian militants in the Gaza Strip.
The 26 men - two Lebanese, five Palestinians and 19 Egyptians - are charged with spying for a foreign group and planning attacks against tourists and shipping in the Suez Canal.
They are also accused of sending operatives into the occupied Gaza Strip to help Palestinian militant groups there.
As the charges were read out, several of the accused reportedly shouted: "We live and die as Egyptians. We will never betray our country."
At least one of the accused said he had been tortured while in Egyptian custody, Reuters news agency reported, adding that he had been referred for medical checks.
A lawyer for the men said the charges against them were "absolutely not true".
"There was never any question in this case of a plot for the assassination of figures inside Egypt," said the lawyer, Montaser al-Zaiat.
Hezbollah has said the charges are politically motivated and in revenge for the movement's stance on Egypt's support for the Israeli blockade of Gaza.
Hezbollah supports Hamas - the Islamic movement which controls the coastal enclave - and has strongly criticised Egypt for not opening its border with Gaza to relieve the Israeli-imposed blockade on the territory.
The trial has been adjourned until October.