For the first time since protests erupted over spiralling fuel prices, soldiers on Monday barricaded key roads in Nigeria's commercial capital of Lagos as President Goodluck Jonathan offered a concession to stem demonstrations he said were being stoked by provocateurs seeking anarchy.

Soldiers and police also barricaded entrances to protest venues in Nigeria's second-largest city of Kano on Monday, including a park near a university and a square in the city centre.

The deployment of troops is a sensitive issue in a nation with a young democracy and a history of military coups. Jonathan said in his televised speech early Monday that agitators have hijacked the demonstrations.

Jonathan announced the government would subsidize gasoline prices to immediately reduce the price to about $2.27 US a gallon. The concession might not be enough to stem outrage over the government's stripping of fuel subsidies on Jan. 1 that kept gas prices low in this oil-rich but impoverished nation.

Even with the measure announced Monday, gasoline would still be more than 50 cents a gallon higher than it was just 16 days ago, and anger in Africa's most populous nation where most people live on less than $2 a day is also now aimed at government corruption and inefficiency.

Tens of thousands have marched in cities across the nation.

Soldiers set up checkpoint

In Lagos, a city of 15 million, army soldiers set up a checkpoint Monday morning on the main highway that feeds traffic from the mainland into its islands. An AP reporter saw more than 10 soldiers carrying assault rifles and wearing camouflage uniforms. Another convoy of soldiers patrolled in a pickup truck.

At a park in Lagos's Ojota neighbourhood on the mainland, where more than 20,000 people had gathered Friday for an anti-government demonstration, two armoured personnel carriers were parked near an empty stage. About 50 soldiers and 50 other security personnel carrying Kalashnikov rifles surrounded the area, waving away those who tried to enter to resume demonstrations. A crowd of several hundred people gathered a few hundred metres away.

"They are here because they don't want us to protest," said Remi Odutayo, 25, referring to the soldiers in the park. "They are using the power given to them to do something illegal" by stopping demonstrators from gathering.

On Lagos' Ikoyi Island, where some of Nigeria's wealthy and some foreign diplomats live, more than a dozen Nigerian air force personnel carrying assault rifles questioned drivers at a roundabout where more 1,000 protesters had regularly gathered last week. Drivers had to slow down because the airmen had put metal barricades and debris in the street.

Wearing a traditional black kaftan, Jonathan was alone on camera as he read from a printed speech on state TV.

"It has become clear to government and all well-meaning Nigerians that other interests beyond the implementation of the deregulation policy have hijacked the protest," Jonathan said. "This has prevented an objective assessment and consideration of all the contending issues for which dialogue was initiated by government. These same interests seek to promote discord, anarchy, and insecurity to the detriment of public peace."

'It has become clear to government and all well-meaning Nigerians that other interests beyond the implementation of the deregulation policy have hijacked the protest.'— President Goodluck Jonathan

Jonathan's speech came after his attempt to negotiate with labour unions failed late Sunday night to avert the strike entering a sixth day. Nigeria Labour Congress President Abdulwaheed Omar said early Monday morning he had ordered workers to stay at home over Jonathan's fears about security, but that might not keep people away from mass demonstrations like one that has seen more than 20,000 people show up in the country's commercial capital of Lagos.

Anger leads to protests

Anger over losing one of the few benefits average Nigerians see from living in an oil-rich country led to protests across the nation, and violence that has killed at least 10 people. Red Cross volunteers have treated more than 600 people injured in protests since the strike began, officials said.

Jonathan and other government officials have argued that removing the subsidies, which are estimated to cost $8 billion US a year, would allow the government to spend money on badly needed public projects across a country that has cratered roads, little electricity and a lack of clean drinking water for its inhabitants.

However, many remain suspicious of government as military rulers and politicians have plundered government budgets since independence from Britain in 1960.

The strike also could cut into oil production in Nigeria, a nation that produces about 2.4 million barrels of crude a day and remains a top energy supplier to the United States.