CAIRO (AFP) - Protestors hurled stones and firebombs at riot police near the Algerian embassy in Cairo on Friday, leaving dozens of officers injured and triggering a diplomatic spat after a crucial football match. Several hundred demonstrators took to the streets following reports of attacks on Egyptian fans in Khartoum soon after their team missed out on a place at the 2010 World Cup finals to bitter rivals Algeria. The violence first erupted on Thursday, a day after the match, with protestors burning Algerian flags and chanting anti-Algerian slogans, as well as the Egyptian anthem. We should treat Algeria like any country that has declared war on us, said Amr Higazi, a university student holding a placard calling for the expulsion of the Algerian ambassador. The unrest spilled over into Friday, leaving 35 police officers injured and 15 cars damaged, Egyptian authorities said, adding later that security forces also arrested 20 of the protestors. The riot police blocked access to the street that led to the embassy, in the affluent neighbourhood of Zamalek, and herded away about 30 protestors, some of whom trampled on and burned Algerian flags. Egyptian leaders weighed in to the football dispute after fans said stones were thrown at their bus on Wednesday as they made their way to Khartoum airport after the 1-0 defeat. In Algeria, meanwhile, at least 14 people died and more than 250 were injured in traffic accidents during celebrations following the World Cup victory over Egypt, authorities said Friday. In the most serious single accident, five people died in the southern district of Ouargla, the civil protection service was quoted as saying in the press. People had taken to the streets in Algiers after the match in Cairo, attacking 15 offices belonging to a local subsidiary of Egypts Orascom Telecom and twice ransacking the Algiers offices of Egypt Air. Arab League chief Amr Mussa called Friday for calm in the row between Algeria and Egypt. I call for a return to calm and reason on the Arab street. The affair must be restored to its true proportions, after all the Egyptians like the Algerians are Arabs, Mussa, in Dubai for a forum organised by the World Economic Conference, told AFP.