Dozens of people have been killed in a ferocious shooting attack on two villages in Nigeria's western state of Kwara, according to authorities and rights groups.

The attackers also set fire to shops and homes, along with the residence of the traditional leader, forcing the residents of Nuku and Woro to flee, local lawmaker Saidu Baba Ahmed told BBC Hausa.

Officials have blamed jihadist groups and deployed an army battalion to Kwara's Kaiama constituency.

Tuesday's attack, one of several across Nigeria in the last few days, comes as the country's defence minister confirmed to the BBC that a small team of US troops was in the country to help with intelligence and training. 

Nigerian President Bola Tinubu said Islamist militant group Boko Haram was behind the attack. Local lawmaker Mohammed Omar Bio said Lakurawa, an armed group affiliated with Islamic State, was responsible, according to the Associated Press. 

Kwara State Governor AbdulRahman AbdulRazaq said 75 local Muslims "were massacred in cold blood simply for refusing to surrender to extremists who preached a strange doctrine". 

Ahmed initially told BBC Hausa that at least 35 people had died, but human rights groups have since reported more than four times that number of deaths. 

A Red Cross official in Kwara, Babaomo Ayodeji, told AFP that "reports said that the death toll now stands at 162, as the search for more bodies continues". 

Several people were abducted in the attack that was undertaken in a "stunning absence of any form of security for the protection of lives", the human rights group said while calling for an investigation. 

A further 21 people were killed in an attack on Doma village in the state of Katsina, they added. The attacks come alongside the first official acknowledgement from Nigeria of an American troop presence since US President Donald Trump ordered the military in November to prepare for action in Nigeria to tackle Islamist militant groups. 

Defence Minister Chrisopher Musa did not provide details on the team's size, arrival date, location or duration of stay. His comments follow those made on Tuesday by Gen Dagvin Anderson of US Africa Command (Africom), who said the deployment followed a Nigerian request and was focused on intelligence support. 

"Our partnership with Nigeria is a great example of a very willing and capable partner who requested the unique capabilities that only the US can bring," he said. 

Nigeria faces an array of security challenges including criminal gangs - known locally as "bandits" who loot and kidnap for ransom - an Islamist insurgency, clashes over land and separatist unrest. 

Kwara police spokesperson Adetoun Ejire-Adeyemi told the BBC that the attack on the neighbouring villages of Nuku and Woro began at 17:30 local time on Tuesday - and she blamed suspected bandits.

She added that various security forces had now been deployed to the area but details of casualties were still unclear as were reports that people were missing.

The whereabouts of the traditional king are reportedly unknown.

Ahmed, the local MP, said the attack on Woro came after several smaller attacks in the area in recent days.

"They started shooting sporadically, they burnt shops, at least 35 bodies have been retrieved - more bodies could be retrieved because people ran into the forest with gunshot wounds," he told BBC Hausa.

"It was complete chaos... Everybody is terrified."

For years the bandits have mainly targeted those in the north-west of Nigeria - but they have been moving to other parts of the country, like Kwara and Niger states, more recently.

Some jihadists - suspected to be from a Boko Haram splinter faction - have also been active in Kwara, carrying out targeted killings, often riding in on motorcycles and attacking markets and vigilante groups set up to protect villagers.

The Kwara governor said Tuesday's attack was a result of recent counter-terrorism operations in the region.

AbdulRazaq believed the attack was "apparently to distract the security forces who have successfully hunted down several terrorist and kidnapping gangs", his press secretary Rafiu Ajakaye said in a statement. 

Also on Tuesday, in the north-eastern Borno State, 17 people were killed in a series of attacks by suspected Boko Haram militants.

The US and Nigerian forces have conducted joint training programmes and exercises for decades.

But the US military has recently become more involved - launching airstrikes on Christmas Day on two camps run by Lakurawa in the north-west.

Late last year, the White House pressed Nigeria's government to improve security and strengthen protections for Christian communities.

Trump had previously claimed Christians were being persecuted in Nigeria - an allegation strongly rejected by Nigeria's government, which said Muslims, Christians and people of no faith were victims of attacks.

There are more than 250 ethnic groups in Nigeria, which is roughly divided into a mainly Muslim north, a largely Christian south, with intermingling in the middle.

Nigeria's Foreign Minister Yusuf Tuggar said the Christmas-Day strikes were approved by President Bola Tinubu and involved Nigerian forces.

Since then security co-operation between the two nations has increased - with the US saying last month that it had delivered critical supplies to support Nigeria's security efforts.

Nigeria's military then told the BBC the equipment had been purchased earlier to aid counter-insurgency operations.

In recent weeks, Nigerian forces have stepped up operations against armed groups.

On Sunday, the army said it had killed a senior Boko Haram commander and 10 other militants during an operation in Borno state. Additional reporting by Mansur Abubakar