What to know about the militants targeted by US airstrikes in Nigeria

US President Donald Trump posted on social media about the ‘powerful and deadly’ strikes (Alex Brandon/AP)

The United States airstrikes that targeted Islamic State militants in northwestern Nigeria on Thursday marked a major escalation in an offensive that Nigeria’s overstretched military has struggled with for years.

US President Donald Trump said on social media that the “powerful and deadly” strikes were carried out against so-called Islamic State (IS) militants “targeting and viciously killing, primarily, innocent Christians.”