A hard-line Islamist group in Somalia claimed responsibility on Monday for bombings in Uganda that killed 74 people, adding new evidence that an influx of foreign fighters linked to al-Qaeda have made them a major international threat in the Horn of Africa.

Al-Shabaab has professed allegiance to al-Qaeda and is trained by operatives sent by the group, according to Western security experts. Sunday’s bombing was emphatic and bloody proof of how sophisticated the group has become in the years since it split from more moderate Islamic groups in Somalia and came to take control of much of the country.

Read the complete story(Some news sites require registration)