Bangladesh's interim government has imposed an indefinite curfew in the capital Dhaka and five other cities following protests by students.Fahim Munaim, a spokesman for the army-backed government, said: "All universities and the colleges of the six cities have been ordered closed for an indefinite period."Students in all universities in these cities have been asked to vacate their dormitories, by 8pm (3pm UK time) tonight, before the curfew begins."The protests which started at the Dhaka University on Monday have spread to other institutions in the capital and across the country and may pose a serious challenge to the government, according to political analysts.The fighting followed an attack by troops on students protesting against the presence of soldiers at a football match at Dhaka University.Troops had been based at the university campus since January when an interim administration took power after months of political violence in the country.Before ordering the curfew, a government statement said the authorities would take "stern actions against anyone engaged in rowdy and anarchic acts".The government withdrew the army camp from the Dhaka University campus on Tuesday night and promised to punish the offenders, in a bid to cool the protesters."Despite these measures a section of people are engaged in causing damage to public and private properties in Dhaka and other places. This cannot be allowed to continue," the statement said.Police and witnesses said a rickshaw puller was killed after he was caught in clashes between police and students at a university in the northwestern city of Rajshahi. At least 100 students were injured, witnesses said.Another 100 people were injured in Dhaka when riot police fired rubber bullets and teargas.A police officer said: "The city is in turmoil, there is smoke billowing from burning tyres."© Independent Television News Limited 2007. All rights reserved.