An Egyptian security official said Saturday that the death toll from clashes between Islamist protesters and security forces the day before had risen to 17.
The official spoke to AP on condition of anonymity, but local media have also reported the death toll rise.
Backers of Morsi's Muslim Brotherhood, a group now labeled a terrorist organization by Egypt's military-installed government, defied a protest ban and took to the streets in their thousands on Friday.
As security forces moved in disperse them, clashes ensued and shots were fired during running street battles in Cairo, Alexandria, Ismailia, Minya and Fayoum. In many cases it is as yet unclear who fired on whom or whether the dead were protesters, members of the security forces or bystanders.
"The martyrs were killed by the security forces' gunfire in several governorates," a Brotherhood-led alliance was quoted as saying in a statement to news agency DPA.
The interior ministry said that 122 Brotherhood supporters had been arrested, alleging they were carrying homemade grenades and Molotov cocktails. The Brotherhood said its protests were peaceful, though an Associated Press cameraman reported seeing dozens of demonstrators carrying home-made pistols.
Crackdown on protests
Protests have been staged almost every day, especially on Fridays after prayers, since Morsi was ousted by the army in July. More than 1,000 people have been killed since then, with hundreds killed during a military crackdown to clear a pro-Morsi protest camp in August.
As a result of the violence, the number of people protesting has dwindled. Late last year Egypt's government declared the Muslim Brotherhood a terrorist organization. Terrorism-related charges carry the death penalty under Egyptian law.
But the Muslim Brotherhood has vowed to continue demonstrating ahead of two milestone events in the country.
On January 8 Morsi is to face a second session of a trial on charges of inciting the killings of protesters while he was president. On January 14 and 15 the country is to vote on a new constitution. Morsi supporters are urging citizens to boycott the referendum.
bk/pfd (AFP, AP, Reuters, dpa)