Nigeria has closed its land borders to all movement of goods and has no timeline for reopening them, the head of the nation’s customs agency said, as part of an effort to curb smuggling.

“All goods for now are banned from being exported or imported through our land borders and that is to ensure we have total control over what comes in,” Hameed Ali, comptroller-general of the Nigerian Customs Service, told reporters in Abuja on Monday.

Africa’s largest economy launched a partial border closure in August as part of an effort to thwart smuggling of rice and other goods, and there had been widespread local media reports of a broader closure.

But Ali’s announcement was the first official confirmation of a total shutdown in trade across Nigeria’s land borders - including goods that had been moving legally.

“We are strategising on how best the goods can be handled when we eventually get to the point where this operation will relax for the influx of goods,” he said. He did not give a timeline for any relaxation of the controls.

The closure has no impact on Nigeria’s economically crucial oil exports, which are shipped out almost entirely via the nation’s seaports and offshore oil platforms.

Ali added that despite the land border closure, it would still be possible for goods to cross at points equipped with special scanners, but did not say where those locations were.

Ali said reopening the borders would depend on the actions of neighbouring states, and that as long as they and Nigeria were not in accord on what goods should be imported or exported overland, the frontier would remain shut.

The move is likely to make a variety of food items, such as rice, tomatoes, poultry and sugar, more expensive for consumers. While it was illegal to bring these items into the country via land borders even before the border closure, they had been widely smuggled.

“Already we are seeing effects on prices and inflation and I’m guessing we will see effects on Q3 GDP once that data comes out in November,” said Nonso Obikili, director at the Turgot Centre for Economics and Policy Research in Abuja.

Exports are also restricted, which will stop movements of cocoa and sesame seeds via land borders, Obikili said.

Ali noted that legal exports could continue via seaports, but Nigeria’s congested terminals and dilapidated road and rail networks make it difficult to quickly change export routes.

Deliveries of gasoline in Nigeria had also dropped by nearly 20 percent during the early stage of the border closure, according to the Petroleum Products Pricing Regulatory Agency.

Gasoline, whose prices is capped in Nigeria, is frequently smuggled across land borders and sold in neighbouring countries.