The militant group al-Shabaab said the man who carried out a suicide bomb attack on a base in Mogadishu this week was a Somali-American, and an official said Thursday that separate clashes with militants in Somalia's capital left at least 17 civilians dead. Al-Shabaab said on its website Thursday that a 25-year-old man named Abdullahi Ahmed was the suicide bomber who attacked an African Union peacekeeping base in Mogadishu, Somalia's capital, on Monday, killing two AU troops and one government soldier. Ahmed was said to have moved to Somalia from Minnesota two years ago. The Internet report purported to quote Ahmed before his death saying that he wanted to carry out the attack because of abuses by Christians of Muslim countries.