BBC News with Gaenor Howells

The Egyptian authorities say at least 73 people have died and more than 1,000 injured in northeast Egypt in clashes between rival football fans. The violence in the city of Port Said began when fans invaded the

pitch

after the home team al-Masry won a rare 3-1 victory against the visiting Cairo-based team al-Ahly. The deputy health minister described it as the biggest disaster in Egypt's football history. Jon Leyne, who's in Cairo, watched live coverage of the clashes.

It's a soccer disaster clearly, and soccer fans here are pretty notoriously violent at the best of times. But I think also a lot of people here (will think) are already suggesting on social media that there's a political element to this as well. The al-Ahly fans, known as Ultras, have become very political recently and have been involved in a lot of

confrontations

with the police. So whether there's any justification or not, a lot of people will say and have been saying that perhaps this is a way of

getting revenge on

them. And I think again that suspicion could lead to more violence on the streets in Egypt in the coming days.

The Nigerian authorities say the growth of informal gold mining in the north of the country is

putting the lives of thousands of children at risk

. More than 700 children have already died in Zamfara state from lead poisoning produced by dust from the mining.

New rules restricting the carrying of firearms have come into force in the Colombian capital Bogota. The temporary measure was introduced by Bogota's new mayor Gustavo Petro. Arturo Wallace has the details.