Nigeria's leading labour group started a general strike on today but oil exports from Africa's top producer continued to flow to world markets, oil and shipping industry sources said.
The strike, in protest at recent gasoline price increases, began on a faltering note after a court ordered the action reversed in return for a withdrawal of the price hikes.
Though banks and businesses in Nigeria's commercial hub of Lagos and the capital Abuja were closed, some public transport was operating and a number of civil servants reported for work, defying the union's stay-at-home order.
There was a heavy police and army presence at main roads, government buildings and the main business district of the two cities.
Tankers continued to load at crude oil terminals and there was no sign of disruption to Nigeria's 2.3 million barrels per day of oil production.
"Our township offices are not fully staffed, but our field oil and gas operations, including exports, are running smoothly," Mr Sola Omole, ChevronTexaco's spokesman said in Lagos.
"Crude oil loadings haven't been affected," said a senior manager with a leading shipping agent in Lagos.
Nigeria's biggest producer, the Royal Dutch Shell said it was still too early to tell whether operations were disrupted, but said they were monitoring the situation and had put in place contingency measures.