Several villagers, including three policemen have been killed in Gamboru Ngala town in Borno State, North East Nigeria, following Boko Haram militant attack on the border town between Nigeria and Republic of Cameroon in the early hours of Tuesday.

This is even as US officials have said they are worried that many of the schoolgirls who were abducted in Nigeria last month may have now been smuggled across Nigeria’s borders into other countries which could complicate the search for them.

The policemen which include a sergeant were attached to Gamboru Ngala Police Station. They were said to have been burnt alive, after gunmen attacked the station and locked them up in one of the offices before setting the police station on fire.

Aside those killed and injured, property worth millions of naira including dozens of vehicles were burnt at the weekly market which usually hold on Mondays.

The sect also burnt houses and killed those they found inside as they chanted ‘Allahu akbar’ and other songs during the raid on the township, said a military source .

The Islamist militants also stole bags of foodstuffs and escaped with them in several vehicles.

The source said some residents of the area fled to safe locations in neighbouring Cameroon close to the Gamboru Ngala town.

The government is still searching for the 276 students, who are aged 16 to 18, who were kidnapped in the northeast of the country by Boko Haram, an armed group designated by Washington as a “terrorist” organisation.

“We cannot close our eyes to the clear evidence of barbarity unfolding before us in Nigeria,” said Democratic Senator Amy Klobuchar, who was addressing the US Senate.

As anger and frustration escalates in Nigeria at the government’s failure to find the girls, six US senators have introduced a resolution calling for action.

“We and our African allies should do everything to help the Nigerian government rescue innocent girls and return them to their families,” Senator Dick Durbin, one of the resolution’s sponsors, said in a tweet, the AFP news agency reported.

The comments came as Boko Haram, whose name translates as “Western education is sinful”, claimed responsibility for the abduction on Monday and threatened to sell the girls.

In a 57-minute video obtained by AFP, Abubakar Shekau, the group’s leader, said: “By Allah, I will sell them in the marketplace.”

State Department spokeswoman Marie Harf condemned the abduction as “despicable” and said the US was standing by to assist “in any way we think that is appropriate”.

However, she declined to outline specific US help and dismissed suggestions that Washington would deploy military assets on the ground.

Under Secretary of State Sarah Sewall is on her way to Nigeria and will meet senior officials in the coming days to discuss the crisis, Harf said.

On Sunday, President Goodluck Jonathan sought help from US and other countries including Britain, France and China to find the girls.

Boko Haram stormed the all-girl secondary school in Chibok on April 14, placing the teenagers, who had been taking exams, onto trucks and disappearing into a remote area along the border with Cameroon.

Defense Information Director, Maj. General Chris Olukolade, in a telephone interview from Abuja, said information concerning the attack has been forwarded to his office but they were scanty.

“I would get back to you as soon as I have details. Right now what I  have is very scanty. But I can confirm that there was an attack at a village in Borno, by gunmen.