The sources did not identify the gunmen, but the attack on Tuesday was the latest in a border area where Benin faces growing spillover from a jihadist conflict in the Sahel and where criminal gangs and smugglers also operate.

"The information about the loss of seven of our compatriots is confirmed," an army source told AFP, when asked about the attack.

Another security source also confirmed the attack.

No group immediately claimed responsibility and the army has yet to comment officially.

West Africa's Gulf of Guinea countries Benin, Togo, Ghana and Ivory Coast are all bracing for the fallout from growing jihadist conflicts in the Sahel across their northern borders.

Benin borders Burkina Faso and Niger, where jihadists linked to Al-Qaeda and the Islamic State group are fighting wars.

In May, Benin troops killed eight suspected jihadists in the northeast of the country near the border with Niger.

A coup in Niger last July has also led to the withdrawal of French troops based there, heightening worries over worsening insecurity across the Sahel.

Benin authorities have sent 3,000 troops to reinforce the border as part of Operation Mirador to counter threats.

The European Union in April said it would provide 50 million euros ($54 million) to help the Benin armed forces to fight against terrorism, especially for reconnaissance aircraft and drones.

Benin's government rarely comments about violence on its borders, but officials have acknowledged that since 2021 they have seen around 20 incursions.

- Border tension -

In May 2019, two French nationals on a safari in Benin were kidnapped in the Pendjari national park, one of the last wildlife sanctuaries in West Africa, which extends in northern Benin for 5,000 kilometres (3,100 miles) along the border with Burkina Faso.

Their Beninese guide was killed during their kidnapping. The pair were released a week later by French special forces at the same time as a South Korean and an American who had been captive for 28 days.

Two French soldiers lost their lives during the operation.

The Benin border with Niger is also a source of tension, with the frontier still closed on the Niger side.

President Patrice Talon has urged Niger's military rulers to cooperate and reopen.

Neighbouring Togo's government has said it reported more than 30 deaths last year from "terrorist" attacks in the country's north, in a rare statement about security.

Last year, President Faure Gnassingbe also said "jihadists" had killed about 140 people, including around a hundred civilians, since their first attacks at the end of 2021.