Boko Haram gunmen killed at least 54 Nigerians Monday night when they simultaneously attacked a military base and a nearby police barracks in the northeastern town of Buni Yadi, authorities said.

Twenty-four soldiers and 21 policemen were killed, including one female police officer, according to Constable Abdullahi Mohammed.

A witness who went only by the name of Mustafa told Reuters the attackers arrived in an armored personnel carrier and six Toyota Hilux pickup trucks, before dismounting and firing rocket-propelled grenades into both locations.

Buni Yadi was the site of another Boko Haram attack in February where the Islamist militants, whose name means “Western education is sin,” killed 58 students at a government college.

Boko Haram militants are also suspected of killing nine people in two remote villages in Nigeria's Borno state Monday night, local official Nglamuda Ibrahim told Al Jazeera. As is typical for Boko Haram attacks on civilian villages, the Islamic militants burned down victims' homes and hoisted their white flag.

Meanwhile, Nigerian authorities claim they have located the more than 200 schoolgirls Boko Haram abducted last month. U.S. authorities said Tuesday that they could not confirm this information. "We don't have independent information from the United States to support these reports you referenced," U.S. State Department spokeswoman Jen Psaki told Reuters.

Boko Haram’s main goal is to establish Shariah law in Nigeria, where they believe Western influence, particularly when it comes to education, has corrupted society.