Protests and violence have continued into the night in Egypt as thousands defied overnight curfews imposed by President Mohammed Morsi.Marches took place in the cities of Port Said, Ismailia and Suez after dark, despite the curfews and a temporary state of emergency.Dozens of people have been killed in five days of violent protests.Meanwhile Mr Morsi's call for national dialogue has been rejected by his political opponents.He had urged opposition leaders to attend a meeting on Sunday evening in an effort to calm the situation, but only Islamists already aligned with the president turned up.The latest protests in the cities along the Suez canal were sparked by death sentences handed down by a Port Said court on 21 local football fans involved in deadly riots at a football match in the city almost a year ago.Elsewhere Egyptians more broadly opposed to Mr Morsi's authority have taken to the streets in the wake of the Egyptian revolution's second anniversary.More deaths on Monday mean that between 50 and 60 people are now believed to have been killed in violent clashes with security forces since Thursday.Earlier, state news agency Mena reported six deaths in Port Said during daylight hours on Monday, when funerals were held for three people killed on Sunday.After nightfall, groups attacked police stations, and one man was killed according to medical sources.Security men and soldiers were also injured, Egyptian authorities said, but troops in tanks and armoured vehicles in Suez and Port Said did not appear to be intervening to uphold the curfew. 'Excessive force'In Suez, people defied the curfew to march towards the headquarters of the provincial government.In Cairo, where no curfew has yet been imposed, violence continued on Monday with one man killed by gunfire near Tahrir Square.Clashes between protesters and police appeared to centre around the Qasr el-Nil bridge that leads onto the square.State TV said a total of 590 people had been injured in violence across Egypt on Monday alone, with most of them in Port Said.In response to the growing violence on the streets, Egypt's cabinet approved a draft law allowing the army to participate in policing and have the power of arrest. The bill was later passed by the Shura Council, the upper house of parliament.The text of the bill says the army will "support the police in maintaining order and protecting vital installations until the end of parliamentary elections and whenever the National Defence Council [headed by Mr Morsi] requests it".Meanwhile the human rights group Amnesty International condemned the use of violence by Egyptian security forces dealing with protests citing "disturbing eyewitness accounts of excessive force... including instances of lethal force". 'Form, not content'Mr Morsi's call for dialogue appeared to fall on deaf ears, both in the streets and among political opponents.Mohamed ElBaradei, a leading member of the opposition National Salvation Front, told journalists that before it would attend any national dialogue, the president would have to appoint a national unity government and take steps to amend the disputed constitution."The dialogue to which the president invited us is to do with form and not content," Mr ElBaradei said."We support any dialogue if it has a clear agenda that can shepherd the nation to the shores of safety."Former presidential candidate Hamdeen Sabahi, speaking at the same news conference, said: "We aspire to a dialogue, but there are no guarantees that this dialogue will be a success... while blood is being spilled."Mr Morsi invited representatives from 11 political forces - Islamists, liberals and leftists - to come to the presidential palace for talks on Monday evening, but only Islamists attended.