At least one person has been killed in Nigeria as violence erupted during angry protests against the doubling of fuel prices.
Hundreds of demonstrators took to the streets in the commercial capital, Lagos, on Tuesday to vent their anger over a government measure to remove a popular fuel subsidy.
Protesters shut down petrol stations, formed human barriers along motorways and hijacked buses as police used riot control tactics to control them. Witnesses said security forces shot one man at a demonstration after a mob assaulted a Nigerian soldier.
Meanwhile, in the central city of Ilorin, another violent protest left one man dead.
The National Labour Congress accused police in Ilorin of shooting the "anti-fuel hike protester".
However, Dabo Ezekiel, the Kwara state police spokesman, denied the claim saying the man was stabbed by motorcycle-taxi drivers angered because they believed he was against their cause, the Associated Press news agency reported. Ezekiel could not say what triggered the attack.
The violence is a sign of growing unrest over the government's hugely unpopular decision to end a two-decades-old subsidy programme that had kept gas affordable.
An Associated Press reporter at the demonstration in Lagos said the protest started early on Tuesday with demonstrators lighting bonfires along the expressway and vandalising gas stations.
The government's quiet announcement over the weekend that the popular subsidy would be shelved, has led to demonstrations in major cities across the country.
Nigeria's government says it will transfer $8bn it would save by cancelling the subsidy to much-needed infrastructure projects.
Even so, Oladipo Fashina, a union leader, has described the move as "immoral and politically suicidal'' and he has urged Nigerians to resist "with everything they have".
Previous attempts to even tamper with the subsidy have been met with nationwide protests.
A group of protesters went on Tuesday to petrol stations in Lagos, telling owners not to sell the commodity at the revised prices of about $0.94 cents per litre.
The price is more than double what consumers paid only days ago for the fuel needed to power generators that keep many businesses running in Nigeria.
Locals describe the nation's electricity supply as sporadic at best.
President Goodluck Jonathan announced on Monday evening that he had set up a committee to ensure that the savings from the subsidy's end will be invested effectively to improve the lives of Nigerians.
Few people have seen any benefit from the vast oil wealth of Africa's most populous nation after decades of production, and a culture of distrust of government permeates Nigerian society.
The protests over rising gas prices are only adding to Nigeria's security woes. Jonathan had already declared a state of emergency over the weekend in parts of the country hit by a growing Islamist campaign that is fuelled in part by widespread poverty.
The fuel-price rise is likely to result in especially high prices in the landlocked north because Nigeria's refined oil is mainly imported through ports in the south.
Police officers dispersed on Monday afternoon a protest in the capital, Abuja, using tear gas and arrested five people including a former lawmaker.