By Shadi Bushra and Ali Abdelaty
CAIRO (Reuters) - An Egyptian court sentenced a prominent activist to five years in jail on Monday for violating limits on demonstrations, amid one of the toughest crackdowns on dissent in Egypt's history.
After the verdict was read, chants of "Down, down with military rule!" rang out in the crowded courtroom from supporters of Alaa Abdel Fattah, a leading secular figure in the 2011 revolt that toppled autocrat Hosni Mubarak.
The blogger and software engineer was originally sentenced in absentia to 15 years in jail, along with 24 others, before a retrial was ordered.
Abdel Fattah is one of several activists jailed since the army overthrew Islamist president Mohamed Mursi in mid-2013 and cracked down on his Muslim Brotherhood movement and secular democracy activists.
Laila Seif, Abdel Fattah's mother, said she hoped her son would draw on the strength that helped his father, a human rights lawyer, through a five-year sentence under Mubarak.
Another defendant, Ahmed Abdulrahman, also received five years in jail; 18 other accused received three years; and others who were tried in absentia were given 15 years. Abdulrahman's lawyer said his client would appeal.
The same court also adjourned to March 8 the trial of two Al Jazeera television journalists charged with aiding a terrorist organisation - a reference to the Muslim Brotherhood.
The United States said it was "deeply troubled" by the sentences and urged the defendants to pursue all legal avenues to contest the verdict, including an appeal.
State Department spokeswoman Jen Psaki said the United States encouraged Egypt's leadership to quickly complete a review of the law on demonstrations and of all verdicts issued under it, and to release an amended version enabling full freedom of expression and association.
Asked if U.S. support to Egypt's military showed Washington was putting strategic interests above human rights, Psaki said the United States had an "important strategic relationship" with Egypt.
But a State Department official said Washington had not yet decided whether to release $1.3 billion in foreign military financing to Egypt set aside for fiscal 2015.
Egyptian activists say that political dissent is being stifled as officials from Mubarak's police state are gradually rehabilitated.