A man who is allegedly responsible for performing over 100 forced abortions on female fighters aligned with the Colombian Marxist group FARC has been arrested in Spain.

The BBC reports that the accused, Hector Arboleda Albeidis Buitrago, had been working as a nurse in Madrid.

Colombia, which has been moving towards a long term peace agreement with FARC, has announced that they are investigating around 150 cases of ex-FARC fighters who say they were forced to terminate their pregnancies.

The Central American nation is seeking Buitrago's extradition.

Attorney General Eduardo Montealegre explained to the media that female FARC rebels who got pregnant were made to terminate their pregnancies as a way to keep them battle ready. "We have evidence to prove that forced abortion was a policy of the Farc that was based on forcing a female fighter to abort so as not to lose her as an instrument of war," said Montealegre.

An ex-fighter named Natalio Cosoy claims to have been forced to have five abortions. According to Cosoy, women were expected to fight and those that were allowed to bring their babies to full term were considered lucky.

Despite his efforts towards peace with the rebels, Colombian President Juan Manuel Santos recently made it clear that his administration would punish crimes that occurred during the half-century of fighting between the two sides.

According to CNN, he said, "We have agreed to create a special jurisdiction for peace that is going to guarantee that the crimes committed during the conflict, especially the most serious ones, will not remain unpunished."

Over 220,000 people have been killed in the war between FARC and the Colombian government.

A final peace agreement is expected in March. Should the agreement be successful, FARC will join Colombia's political process legally.