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,
Meanwhile in the central city of Ilorin, another violent protest left one man dead.
The National Labor Congress accused police in Ilorin of shooting the "anti-fuel hike protester".
However, Kwara state police spokesman Dabo Ezekiel 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 program 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 Nigerian government's quiet announcement over the weekend that the popular subsidy would be shelved has led to organising in major cities across Africa's most populous nation of 160 million.
Nigeria's government says it will transfer $8bn it would save by cancelling the subsidy to much-needed infrastructure projects.
Even so, union leader Oladipo Fashina 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.
On Tuesday, a group of protesters went to gas stations in Lagos, telling owners not to sell gas at the spiked 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 country's vast oil wealth 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 Islamic insurgency that is fuelled in part by widespread poverty.
The fuel price hike 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.
On Monday afternoon, police officers dispersed a protest in the capital of Abuja using tear gas and arrested five people including a former lawmaker.