Several of Nigeria’s struggling oil refineries are back in production and making enough gasoline to help stabilize supply in the country, a spokesman for the Nigerian National Petroleum Corporation (NNPC) said, Reuters reported.

NNPC informed that the Port Harcourt, Warri, and Kaduna refineries were producing a total of 6.76m liters of gasoline per day, adding that this was projected to rise to more than 10m liters per day by the end of January. All of the country’s refineries had been shut down for months until late December, and traders have said new production could face quality issues as a result.

Despite being one of Africa’s biggest oil exporters, the country imports nearly all its gasoline as it has struggled to produce fuel at its ageing refineries, which have suffered from years of neglect and perennial sabotage.

Nigeria has been facing pipeline vandalism in the Niger Delta, which costs the state and oil companies $14b a year and has devastated up to 52,000 hectares of land in 2014, according to earlier estimates by a leading Nigerian Research and Development Group.

In addition, Nigeria has been tackling illegal oil market – valued at more than $20m a day for many years without a major success. Previously in mid December 2015, it was reported that in line with country’s zero tolerance policy for maritime illegalities, the Nigerian Navy had arrested over 20 vessels and their crews, and destroyed some 149 illegal refineries.