The judge in the trial of Egypt's deposed President Mohamed Morsi has ordered the hearings adjourned until February 1 after bad weather prevented bringing Morsi to court, according to state media.
State media reported that the helicopter that was to fly Morsi from a prison near the Mediterranean city of Alexandria to the court in Cairo could not take off because of fog on Wednesday.
Morsi and 14 others are on trial for inciting the killing of protesters outside a Cairo presidential palace in December 2012, when at least 10 people were killed and hundreds wounded.
It is one of three trials that Morsi faces. Charges in all three carry the death penalty.
Mohammad Salim al-Awwa, Morsi's lawyer and former aide, told Al Jazeera he believed the decision to adjourn the hearing had nothing to do with the weather.
"The decision is purely political," he said. "The authorities do not want protests to erupt following the trial and ahead of the vote in the referendum," he said.
Egyptians in the country are set to vote in the constitutional referendum on January 14 and 15. Voting for expatriates began on Wednesday.
Clashes erupted on Wednesday in Cairo's Nasr City district between pro-Morsi protesters and security forces, injuring several people, Al Jazeera's correspondent said.
Morsi first appeared in court in early November, insisting that he was still president and being held against his will.
A state prosecutor charged Morsi and 14 other Muslim Brotherhood members in 2013 with "committing acts of violence, and inciting killing and thuggery", according to Egypt's state news agency.
The charges relate to violence in which around a dozen people were killed outside the presidential palace in December 2012, after Morsi had angered many Egyptians with a decree that expanded his powers.
The episode was one of the most violent of his presidency.
Tens of thousands of people gathered outside the presidency to demonstrate against Morsi's decree and a divisive, Islamist-oriented constitution that he planned to put to a referendum.
The Brotherhood's leaders called on members to rally to his defence.
Egypt's state news agency says the leaders stand accused of mobilising their followers to forcibly disperse the protesters after the security forces rejected Morsi's orders to do so.
The charges against Morsi include inciting his followers and assistants to commit crimes of premeditated murder and use violence and thuggery.
Morsi was toppled just a year into his term following mass protests fuelled by anger at economic mismanagement and Brotherhood attempts to entrench its power.
His downfall has led to some of the worst violence in Egypt's modern history, in the form of protests by his supporters, a bloody police crackdown on those supporters, and attacks on the police and churches.
At least 900 people, most of them Morsi supporters, were killed in August 2013 after the authorities smashed two protest camps set up by Morsi's supporters in Cairo.