Cairo, AP—Heavy gunfire rang out in the heart of Cairo as tens of thousands of Muslim Brotherhood supporters took to the streets Friday across Egypt in defiance of a military-imposed state of emergency following the country’s bloodshed earlier this week. At least 17 people were killed in the fighting, including police officers.

Military helicopters circled overhead as armed residents set up checkpoints throughout the capital. Police fired tear gas as clashes erupted between Brotherhood supporters and locals opposed to their protest before some reached a key square the group had urged its supporters to converge on.

Protesters and residents of the neighborhoods they marched by exchanged gunfire and birdshot as tanks blocked key roads and key junctures. The Brotherhood urged its supporters in Cairo to head to Ramses Square, near the capital’s train station in the heart of the capital.

A Health Ministry official speaking on state television said eight people were killed in the city of Dumyat north of Cairo. Security officials said all the protesters there were killed by live ammunition when they tried to storm police stations.

A protester was also killed near Ramses Square, security officials said.

The Interior Ministry said a total of eight policemen had been killed throughout Egypt.

The protests were larger and fiercer than in previous weeks, ignited by the outrage over the deaths of at least 638 people on Wednesday when riot police raided two sit-in protests in Cairo by supporters of ousted President Mohammed Morsi.

Soldiers blocked access to the landmark Tahrir Square in Cairo, where dozens of anti-Brotherhood protesters have been camped out for weeks. Barbed wire surrounded the area.

Men carried assault rifles on the overpass leading to Ramses Square. An Associated Press reporter there saw one protester wounded by a bullet in the leg.

Also Friday, security officials said assailants detonated explosives on train tracks between Alexandria and the western Mediterranean Sea province of Marsa Matrouh. There were no injuries and no trains were damaged from the attack, officials said, speaking on condition of anonymity in line with regulations.
Wednesday’s assault had triggered daylong running battles and deadly clashes between security forces and Morsi-s supporters elsewhere in Egypt. The Interior Ministry later said it authorized the use of deadly force against anyone targeting police and state institutions.

Egypt, the Arab world’s most populous nation, has been sharply polarized since the military removed Morsi from power on July 3, following days of mass protests against him and his Brotherhood group. But Morsi’s supporters have remained defiant, demanding the coup be overturned. The international community has urged both sides in Egypt to show restraint and end the turmoil engulfing the nation.

The Brotherhood’s political wing, the Freedom and Justice Party, said in a statement Friday that the group is not backing down and “will continue to mobilize people to take to the streets without resorting to violence and without vandalism.”

“The struggle to overthrow this illegitimate regime is an obligation, an Islamic, national, moral, and human obligation which we will not steer away from until justice and freedom prevail, and until repression is conquered,” the statement said.
Separately, the Brotherhood’s supreme guide Mohammed Badie, wanted by police for allegedly inciting violence, warned in a statement Friday that removing Morsi was an attempt for the military to take over and establish a “dictatorship”.

The revolutionary and liberal groups that helped topple Morsi have largely stayed away from street rallying in recent weeks.