New York's benchmark West Texas Intermediate light sweet crude for May delivery rose 55 cents to USD 110.85 per barrel after touching its highest level in two-and-a-half years in US trade yesterday.
Brent North Sea crude for May delivery gained 38 cents to USD 123.05.
"Current levels for crude are primarily supported by the Middle East tensions and also the Nigeria elections," said Chen Xin Yi, a commodities analyst with Barclays Capital.
"The postponement of last's week parliamentary polls (in Nigeria) due to logistical problems does not bode well for presidential elections," Chen added.
Nigeria's electoral agency yesterday announced a third delay in legislative polls in some parts of the country after it failed to sort out logistical problems in time for the weekend vote.
Political developments in Nigeria are important for the oil market because the country is Africa's biggest crude oil producer.
The market has been under pressure by tensions in the oil-producing Middle East and North Africa region, where long-time rulers are under threat by uprisings similar to those that deposed the leaders of Tunisia and Egypt.
Libyan leader Muammar Gaddafi is battling to remain in power, with rebels controlling large parts of the country.
Gulf states have also piled pressure on Yemen's embattled President Ali Abdullah Saleh, saying they expect him to quit following more than two months of bloody protests.
Yesterday, the International Monetary Fund warned that crude demand is outpacing the growth of global supplies, a situation that would lead to sustained higher prices over the long term.