KANO, Nigeria: Gunmen have stormed a residence in central Nigeria that housed foreign workers, killing two police guards in an attack a company source said Thursday was a failed kidnapping.

Police in Taraba state confirmed the raid in the village of Tella at the site owned by the Triacta engineering firm, but declined to provide details, including whether the three Lebanese engineers working there were the target.

But an official from Triacta, who requested anonymity, told AFP that "based on what has been happening (recently in Nigeria) we have every reason to believe that our expatriates were the target."

"It was a clear case of a failed kidnap," he added.

"Last night, there were shootings around the house where the expatriate construction workers are living," said resident Yonana Dauda. "Two policemen guarding the house were shot dead."

The company official and other residents confirmed those details, adding that the Lebanese engineers ran when the gunfire broke out and escaped the incident unharmed.

Police spokesman Amos Olaoye said only that there "there was an incident in Tella last night... details are sketchy."

On February 16 gunmen raided a construction site in northern Bauchi state, abducting seven foreigners.

The attack was claimed by Islamist group Ansaru, seen as an offshoot of Boko Haram, a more prominent group of Islamist extremists that have killed hundreds in Nigeria since 2009.

Separately, seven members of a French family, including four children, were abducted near the Nigerian border in Cameroon on February 19.

In a video posted on YouTube, the kidnappers claimed to be members of the Nigerian Islamist extremist group Boko Haram, but their affiliation remains unclear.

Taraba has a long, porous border with Cameroon, but the targeted village, where Triacta has a bridge project, is deep inside Nigerian territory.

Kidnappings have for years been common in Nigeria's oil-rich south, with the abducted foreigners often released following a ransom payment.

Such incidents in the north and centre of the country were once considered rare, but a recent spate of attacks has raised concerns of changing tactics among the Islamist and criminal groups operating in the region.

Taraba lies in Nigeria's middle belt region dividing the mainly Muslim north and predominately Christian south of Africa's most populous nation. The region is regularly hit by outbreaks of violence between Christian and Muslim ethnic groups.

Sectarian riots sparked over a disagreement about a football pitch left at least one dead over the weekend.