Republican U.S. Rep. Michele Bachmann and former GOP congressman Chip Cravaack wrote to Nigeria’s president more than two years ago, raising concerns about the terrorist group that kidnapped more than 250 girls from the African country last month.

Amid mounting international outrage over the mass abduction and the Nigerian government's largely ineffective effort to subdue Boko Haram, authorities admitted this week that the girls likely have been separated and taken out of the country.

The April 2012 letter from Bachmann, Cravaack and three others urged to President Goodluck Jonathan to root out government corruption, increase economic aid to the country’s northern region and develop counterterrorism measures to halt the mounting Boko Haram insurgency. The Islamic militants have operated out of northern Nigeria since at least 2009.

“We write to express our grave concerns about the ongoing insurgency by Boko Haram, the Nigerian-based terrorist organization that has killed an estimated 510 people in 2011 and as many as 160 this past January,” the letter began.

“We certainly recognize that aggressively targeting an insurgency is difficult, especially one like Boko Haram, that has done nothing but grow in strength in recent years. However, any alternative gives Boko Haram time to recruit new converts and develop even more deadly strategies.”

Democratic U.S. Sen. Amy Klobuchar and Republican U.S. Rep. Erik Paulsen are among the lawmakers who have called on President Obama and international leaders to respond quickly to the “heinous crime.”

In response, the Obama administration has dispatched military advisors and hostage negotiators to aid in the recovery efforts.

Bachmann, Cravaack Boko Haram Signed Letter April 2012