Boko Haram jihadists killed 33 fishermen and loggers in two separate attacks in Borno State, northeastern Nigeria, two sources told AFP on Wednesday.

Tens of thousands of people have been killed and millions displaced since the start of the jihadist insurgency led by Boko Haram and its rival the Islamic State in West Africa (ISWAP) 17 years ago.

The resurgence of jihadist attacks in recent months has led the Nigerian army to strengthen its military cooperation with the United States. The two armies conducted joint strikes last weekend and earlier this week in Borno State, eliminating 175 jihadists, according to Abuja and Washington.

On Monday, two jihadist attacks claimed the lives of 27 fishermen in the Mafa district and six loggers in the Dikwa district, according to an anti-jihadist militia and a union official of fishermen in the region.

"The fishermen were intercepted by Boko Haram fighters on motorcycles two kilometers from the town of Mafa," said Babakura Kolo, a member of an anti-jihadist militia assisting the army.

"All 27 fishermen were killed," he said.

Abdullahi Sani, an official with the fishermen's union in Maiduguri, the state capital located about fifty kilometers from Mafa, confirmed the same death toll of 27 victims.

Earlier in the day, six woodcutters were shot dead by Boko Haram fighters while collecting firewood in the bush outside the village of Malam Maja in the neighboring district of Dikwa, Mr. Kolo said.

These loggers were among those displaced by insecurity linked to jihadist activities and were living in makeshift camps in the town of Dikwa, 90 km from Maiduguri, Kolo said.

The jihadists are increasingly targeting loggers, farmers, fishermen, ranchers and scrap metal dealers in the region, accusing them of spying on them and passing information to the army.

Two weeks ago, Boko Haram fighters shot dead 18 loggers who had gone into the bush outside the village of Abaram, in the district of Bama (Borno State), according to an anti-jihadist militia and residents.

Most displaced people live in makeshift camps, dependent on food distributions from international charities.

But with aid drying up due to budget cuts, displaced people are left to fend for themselves.