PORT SAID, Egypt: Parts of a government complex were set on fire as protesters throwing stones and firebombs clashed with police firing tear gas and bird shot Monday in clashes that have caught the military in the middle of fighting in the Egyptian city of Port Said.

The renewed clashes came hours after thousands of city residents rallied in a funeral procession for civilians killed during street battles with police a day earlier in which three policemen and three civilians were killed.

The two days of clashes have dragged in the military to a dramatic extent. Troops trying to break up fighting have been overwhelmed by police tear gas, one army colonel was wounded by live fire, and at some points troops have opened fire over the heads of police.

The scenes have underlined a scenario that many in Egypt view with a mix of concern and relief – that the military may move back into politics, prompted by mushrooming protests, a breakdown in law and order and mounting challenges to the president.

On Monday, the military deployed soldiers and cars to escort the funeral procession. “We want retribution,” the marchers chanted. “It is now war between us and you, Interior Ministry.”

Protesters in the procession, carrying the coffins of the dead to the cemetery, waved the black-white-and-green flags of Port Said that have become a symbol of the city’s revolt.

Violence erupted when protesters on the way back from the funeral hurled rocks at the police headquarters, which lies in a government complex. Police responded with volleys of tear gas.

The military stood by as protesters and police exchanged projectiles, witnesses said. At one point, the military fired in the air to stop the violence. Flames were visible from the provincial government’s headquarters and a nearby tax authority office, adjacent to the police building. Firefighters were unable to reach the blaze.

Amira al-Alfi, a 33-year-old resident of Port Said who watched as the building caught fire, said the scene was confusing.

“The government building is on fire. We don’t know who is aiming at who. But young people end up dying,” she said as she coughed from tear gas.

Medical officials said at least eight people were injured by bird shot.

The wrath among residents of Port Said is aimed at the police force, which many accuse of using excessive force that led to the killing of more than 40 civilians during protests in January. The city has seen the heaviest protests in a wave of unrest around the country in recent months.

In at least two separate incidents in Cairo Monday, protesters torched two police vehicles, setting them on fire and forcing the policemen in the cars to run in the middle of traffic on major thoroughfares.

Port Said has been in turmoil since late January, when a Cairo court issued death sentences against 21 people, most residents of the city, for involvement in Egypt’s deadliest football riot in February 2012. The verdicts sparked angry protests in the city, which turned into deadly clashes with police, leaving more than 40 dead, including two policemen.Residents have been outraged by what they call excessive force by the police and by the central government’s response – President Mohammad Mursi called the protesters “thugs” and has generally backed the security forces.

The fighting Sunday saw the most dramatic instance of the military being pulled into the middle of Egypt’s escalating tensions.

Witnesses described a tense scene between the police and the military during the clashes. The fighting began when thousands of protesters marched on the police headquarters after word emerged that 39 defendants in the football violence case had been transferred to prisons outside the city. The move apparently aimed to ensure calm ahead of Saturday’s hearing in the case.

The protesters Sunday lobbed rocks and firebombs at the police building. The police moved out to try to push back the protesters.

Army officers tried but failed to negotiate an end to the fighting, then pulled back from between the two sides. Then the troops began getting hit. An army colonel, Sherif al-Arayishi, was shot in the right leg by live ammunition, military spokesman Ahmad Mohammad Ali said. Also, soldiers were overwhelmed by the tear gas that police were firing at the protesters. In one case, captured on video, a tear gas canister fell inside a military armored vehicle, and the choking soldiers stumbled out, helped by protesters who carried them to an ambulance.

Then the military moved back in, deploying their vehicles back in the crowds between the protesters and police. They fired in the air in the direction of the police, prompting cheers from the protesters, witnesses said. People chanted at one point: “The people and army are one hand.”

“We had doubted the military, thought it was only there to protect installations. What they did yesterday restored our confidence,” said one protester who had witnessed the scene, Mohammad Atef. “We felt they are feeling the injustices against us; that they decided to protect us too.”

Both the military and the Interior Ministry, which is in charge of the police, sought to dispel any sign of friction. The Interior Ministry issued a statement saying “unknown elements” fired at the police and military with the aim of sowing sedition. In a statement late Sunday, the military denied it fired at police.