Nigerian police fired tear gas on Friday in a bid to disperse student protesters demonstrating over a name change at their university, authorities and witnesses said.The tear gas caused protesters to temporarily retreat, but a couple of thousand were gathered near the gate at the former University of Lagos later in the morning as hundreds of police officers looked on.Lagos Deputy Police Commissioner Tunde Sobulo confirmed tear gas had been fired, saying "students were trying to overwhelm (policemen)." He said officers responded with tear gas to disperse the protesters.Joshua Olawale, a student representative, said police had sought to prevent the protesters from straying beyond the area of the campus."This has been a peaceful protest, but the police are making it as if it is a war situation," he said."They fired tear gas and injured four of our colleagues who are now on admission in the medical centre in the university."Witnesses said protesters had thrown stones and other debris at police vehicles.Nigerian President Goodluck Jonathan announced Tuesday that the University of Lagos, also known as UNILAG, would be renamed Moshood Abiola University.The name change is meant to honour Abiola, a businessman and politician widely believed to have won 1993 presidential elections, but who saw the result annulled by military ruler Ibrahim Babangida.Abiola was jailed after declaring himself president and died in custody in 1998.Students say the name change will harm the university, which is known across Africa's most populous nation and has a strong academic reputation.On Wednesday, protesting students blocked a major bridge in Lagos, Nigeria's economic capital of some 15 million people.