The American and African forces sent to Cameroon to fight Boko Haram have, on several occasions, located clusters of Chibok schoolgirls kidnapped by the militant group two years ago, United States officials have said.

Rescue operations have not been carried out, the officials said, because of fears that any ensuing battle with Boko Haram fighters would put the captives at risk, or incite some form of retaliation against hostages still being held in other areas, the New York Times reported on Wednesday.

American officials said a combination of local intelligence, intercepted communications and drone footage had been used to locate groups of the 276 girls abducted from the Government Girls’ Secondary School, Chibok, Borno State while some of the girls have since been tracked to the Sambisa Forest.

The American officials however insist that efforts to free the girls have not been abandoned, saying a major concern is the hundreds of other women and girls who are often sexually assaulted, forced into marriages with their tormentors, and sometimes killed by Boko Haram fighters.

“You’re not just looking for 200 girls,” said Gen. Carter Ham, the retired head of the United States military’s Africa Command.

“There are many, many others who have been taken hostage, and more thousands killed, and two and a half million people displaced.”

Senior American military officials joined Samantha Power, the United States ambassador to the United Nations, in Cameroon this week to speak with the country’s military and civilian leaders about the fight against Boko Haram and information gleaned by American intelligence.

The talks took place not far from where American Special Operations forces and hundreds of surveillance drone operators are based. Despite the proximity of the troops, Boko Haram’s attacks continued.

On Monday night, three Cameroonian soldiers were killed and five were wounded after Boko Haram fighters ambushed a military convoy near Dabanga, a town in the country’s north, Cameroonian military officials said. The ambush followed intense fighting on the Nigerian side of the border, where Boko militants attacked an army base, wounding 22 soldiers.

US military officials said that intelligence reports show that the girls have been divided into smaller groups.

Gen. David Rodriguez, the head of the military’s Africa Command, told reporters at the Pentagon that the Chibok girls had been “moved to some very isolated places,” noting that locating them is “not an exact science.”

Meanwhile, the Director- General of the Department of State Services, Mr. Lawan Daura, and the Inspector-General of Police, Solomon Arase, have reportedly told the Senate on Wednesday that they did not have concrete clue on the whereabouts of the Chibok girls.

The security chiefs, according to a senator who craved anonymity because of the sensitive nature of the issue, stated this at a closed-session with the federal lawmakers on Wednesday.

The senator said both Daura and Arase said that there was no clue yet on the whereabouts of the abducted girls who have already spent two years in the custody of the dreaded Boko Haram.

Daura said that the government did not really know where the girls were being kept and that a recent attempt to rescue 20 of the girls failed because the insurgents reneged on their promises.

The senator also said that security chiefs explained that the recent attempt at rescuing the girls was as a result of interactions between the government and supposed representatives of the insurgents.

He said that the security chiefs also told the senators that the Boko Haram members had demanded that five of their senior hands, already arrested by the government should be freed in exchange for 20 of the girls.

He said, “The security operatives revealed that the supposed negotiators asked the security men to bring the 20 girls to a location in Maiduguri and that 10 of them will be exchanged for five Boko Haram militants in government custody.

“They said that the government agents were to drop the five insurgents in a location where they would pick 10 of the girls while they would locate the second batch of 10 in another location.

“The security chiefs said that though the five Boko Haram insurgents in government custody were taken to Maiduguri as planned, the deal failed to sail through as the Boko Haram failed to produce the girls.”

The Chief of Army Staff, his counterpart in the Navy and that of Air Force, did not turn up for the briefing on their efforts to rescue the 219 Chibok schoolgirls abducted from their school since April 14, 2014.

However, Arase and Lawal Daura, briefed the senators on their efforts behind closed doors.