(AP) A blast in Ethiopia's capital over the weekend appears to have been an accidental detonation of explosives by two Somali militants who may have planned to attack a soccer game, a state TV report said Monday.
The report came amid heightened concern of attacks by al-Shabab, the Somali militant group that took responsibility for an attack on a mall in Kenya that killed dozens of people last month.
Sunday's blast at a home in Addis Ababa killed two people, both Somalis, state TV reported. The explosion affected a home used by personnel of the U.S. Embassy in Addis Ababa, an FBI document said. There did not appear to be any American casualties from the blast.
Ethiopia's anti-terrorism task force found a gun, grenades, explosives, a detonator and a belt at the home where the explosion took place, state TV reported. The jersey of Ethiopia's national soccer team was found at the site of the explosion, in what was perhaps an indication that the would-be bombers hoped to mingle among soccer fans of a game being played Sunday, the state TV report said.
No militant group has claimed any link to the explosion in Addis Ababa, but the area where it occurred hosts a large Somali population.
Last month in Kenya, 67 people were killed in an al-Shabab attack on a Nairobi shopping mall. Al-Shabab in 2010 detonated bombs in Uganda's capital during the World Cup final, killing more than 70 people.
The Somali militant group said those attacks were retaliation because Kenya and Uganda have troops in Somalia. Ethiopia also has troops in Somalia.
An FBI document obtained by The Associated Press says the blast "impacted the wall of a U.S. employee residence." The U.S. Embassy on Monday warned that a Twitter message purporting to be run by al-Shabab warned that more attacks were planned in Addis Ababa. The embassy said it cannot determine the credibility of the threat.
Experts on terrorism contacted by the AP previously have said the Twitter account is fake.
The U.S. Embassy said it was issuing its warning because many Americans live in Bole, the Addis Ababa neighborhood where the blast occurred. But the embassy said it has no specific information that suggests an imminent threat to U.S. citizens or facilities in Ethiopia.
Associated Press writer Eileen Sullivan in Washington, D.C. contributed to this report.