They said two policemen also were shot to death outside the city's main prison when angry relatives tried to storm the facility.
According to local Egyptian news outlets, protesters set fire to cars and shops, as well as several public facilities, chanting "Port Said needs independence." Security forces deployed in the area fired tear gas at them.
According to Sky News' Arabic channel, armored personnel carriers have been deployed in Port Said to quell the protests. A military source told the British network that a curfew is likely to be imposed in the area, as well as a possible state of emergency declaration.
Riots in Port Said (Photo: AFP)
Egyptian President Mohamed Morsi
has convened an emergency session of the National Defense Council following the riots.
The council condemned street violence and called for national dialogue to resolve political differences, the information minister said after the council met.
The council called for "a broad national dialogue that would be attended by independent national characters" to discuss political differences and ensure a "fair and transparent" parliamentary election, the minister said in a televised statement.
The riots broke out at noon, following a court verdict which sentenced 21 people to death over their involvement in the Port Said
soccer stadium disaster, which occurred in the city in 2011 and claimed 74 lives.
Protest following the verdict (Photo: AFP)
The clashes followed as the country was still reeling from violent riots that took place on Thursday and Friday, claiming nine lives.
The riots broke out as Egypt was marking the second anniversary of the January 25 revolution,
over the people's discontentment with the Muslim Brotherhood's
regime and Morsi's
Cairo has taken a harsh position vis-à-vis the rioters, deploying hundreds of soldiers and police officers across hubs of unrest.