CAIRO (AP) — Egyptian security forces firing water cannon and tear gas clashed across the country with hundreds of rock-throwing supporters of the ousted ex-president Friday and three people were killed, according to authorities.

Another 200 were arrested, including women, as authorities tightened security measures in the capital after Mohammed Morsi’s Muslim Brotherhood and its allies renewed calls for mass rallies.

Friday is the day of the week in Egypt in which protests are typically at their largest. The day’s demonstrations follow an announcement by the authorities that they will use the Brotherhood’s new designation as a terrorist organization to levy harsh prison sentence on protesters, and poses the first test of whether that tactic will deter them.

In Cairo, riot police chased student protesters chanting against the military and the police at the Islamic Al-Azhar University. Footage on private TV networks showed demonstrators hurling stones and setting fire on tree branches to defuse tear gas smoke.

The night before, one person was killed when similar clashes broke near the dormitory of the same university. Anti-Morsi civilians also joined the fray in the eastern district of Cairo, fighting against the protesters, according to Egypt’s official news agency.

Clashes also erupted Friday in several other districts of the capital. Al-Jazeera Mubashir Misr TV showed footage of police vehicle on fire in a highway linking Cairo with Giza.

An Associated Press cameraman in another middle class district, Alf Maskan, saw Islamist protesters hurling Molotov cocktails and fireworks at security forces while civilians, on the police side, hurled stones. The street was littered with rocks, shattered glass and black soot.

A security official says two riot troops of the Central Security Forces were seized by protesters after they were injured in the clashes and they were later released with residents’ help.

In a statement, Egypt’s Interior Ministry said a total of three people were killed. Three police vehicles sat on fire and 265 protesters including women arrested, it said.

Armored vehicles had earlier closed main squares and city centers in Cairo and other major cities in preparation for expected rallies protesting the labeling of the Brotherhood as a terrorist organization. The announcement was meant to further cripple the group ahead of a key vote on draft constitution on Jan. 14 and Jan. 15 seen by the interim government as a milestone in the transition plan.

After the declaration, security spokesman said any participants in Brotherhood rallies will be sentenced to five years in prison, and group leaders could be sentenced to death according to anti-terrorism laws.

Since Morsi was ousted in a military coup on July 3 after millions demonstrated demanding his removal, the Muslim Brotherhood and its allies have held constant protests demanding his reinstatement and denouncing the interim government installed by the military in his place. But their rallies have sharply decreased in numbers because of a heavy-handed crackdown on the group that put thousands in detention and killed hundreds during the violent disbanding of two protest camps in August.

This Friday poses a test to the Brotherhood’s willingness and ability to continue going head-to-head against the interim government in the face of the new penalties.

Outside the capital, the city of Assiut 320 kilometers (200 miles) south of Cairo, a stronghold of Islamic groups, witnessed two small rallies which were quickly dispersed after pro-government civilians fired into the air to drive protesters away.

A security official said that police asked the region’s big families, traditional allies of the security apparatus, to send armed men around police stations and churches in the city and surrounding towns.

The two officials spoke on condition of anonymity because they were not authorized to brief reporters.

The terror label came after a suicide bombing Tuesday in a Nile Delta city that killed 16 and wounded 100, mostly policemen. A second blast took place on Thursday in Cairo, hitting a bus and injuring passengers but leaving no major causalities.

The government accused the Brotherhood of being behind the bombing, as well as stepped-up attacks by Islamic militants since Morsi’s ouster, a claim the group denies. An al-Qaeda-inspired group, Ansar Beit al-Maqdis, or the Champions of Jerusalem, claimed responsibility for Tuesday’s suicide attack and vowed more.

The government has provided no strong evidence that links the Brotherhood to militant groups. But during Morsi’s year in power, he allied with radical groups and sent envoys to militant leaders for a truce in the volatile Sinai region in return for halting military offensive.

After Morsi’s ouster, the military launched a major offensive in Sinai against suspected militants, sweeping through hideouts in villages located near the borders with the Gaza Strip and Israel.

Copyright 2013 The Associated Press.