Nigeria's oil minister has apologized for a crippling fuel shortage that has dragged on since late 2015 in the country that is sub-Saharan Africa's no. 1 oil producer, creating long lines at gas stations and leaving travelers stranded on highways.

Emmanuel Ibe Kachikwu told the Senate this week that the government is "pained" by the crisis and promised to bring an end to long fuel lines by the second week of April. Analysts say it will take longer to resolve a shortage they describe as the product of longstanding refining issues and unplanned pipeline outages.

Fuel lines stretched for more than a kilometer (half-mile) on Friday in Abuja, the capital in central Nigeria. Drivers groaned and shouted in frustration when one station closed apparently because it was out of fuel.