Kano - The raging Boko Haram insurgency in the northeast has hit the region's fishing industry, causing shortages and driving up prices, union leaders say.
Maiduguri has been particularly affected, as the authorities in neighbouring Niger have detained huge consignments of smoked fish on security grounds.
For over a week, more than 200 vehicles loaded with the fish and destined for Borno state have been held outside Diffa, pending searches.
The head of the fishermen's union in Borno, Abubakar Gamandi, said the city and the northern region was now facing an "unprecedented shortage" of fish.
"The fish supply to Maiduguri has been disrupted and prices have soared," he added.
A carton of smoked fish in the city now sells for 15,000 naira against 9,000 naira previously.
"We have no problem with the consignments being screened but for 10 days now none of these vehicles has been searched, they are just kept there," Gamandi said.
The vehicles are carrying fish worth 1.12 billion naira, which traders in the beleaguered city bought by pooling their depleted capital.
"Our traders have suffered so much financial setback as a result of the Boko Haram insurgency, and if they lose these consignments which are their lifeline the economic effect will be catastrophic," Gamandi said.
An official of the drivers' union in Diffa confirmed that more than 200 vehicles were lying outside the city.
"It is only the vehicles with the fish that are being detained, but passenger vehicles are allowed passage after screening," the official said, asking not to be named.- Supply route cut off -
Diffa has in recent weeks been hit by a spate of suicide bombings and cross-border raids by Boko Haram in response to Niger's decision to deploy troops against the militants.
The government in Niamey earlier this month imposed a 15-day state of emergency in the Diffa region, leading to increased security.
Borno state once prided itself as a major fishing hub, sourcing produce from Lake Chad, where the borders of Nigeria, Niger, Chad and Cameroon meet.
But the Boko Haram conflict, which began in 2009, has disrupted fishing on the Nigerian side of the lake, especially in Baga and Marte.
Boko Haram fighters captured Baga in a devastating raid on January 3, killing hundreds, if not more, and forcing thousands of others to flee, many of them fishermen.
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Nigeria's military said Saturday that troops had regained control of the town.
The years of violence -- and the risk of being forcibly conscripted into the Boko Haram ranks -- has forced thousands of fishermen to abandon their trade.
Many turned to importing fish from Chad and Niger, whose shores were not affected by the insurgency. But the fall of Baga cut off the traders' supply route.
Suleiman Alagarno, a trader at Maiduguri's Gamboru fish market, said there were fears that the consignment currently stuck in Diffa will be destroyed if it is not released.
"It is sealed in cartons and loaded in vehicles with no ventilation," he said, adding that the risk of running out of fish in the coming days was high.
The effect of the shortage is being felt across the wider north of the country.
Shehu Aliyu is a fish dealer in Hadejia in Jigawa state, 350 kilometres away and relies on Maiduguri for supplies.
"I came to Maiduguri to find out what the situation is because supplies to Hadejia have stalled and the demand is so high," he said.
"Customers have been bothering me about why I no longer supply them with fish and I'm here in Maiduguri to see how I can get some fish no matter the quantity to make them happy."