Ethiopia ? Nine bombs exploded Friday across Ethiopia’s capital, killing four people and wounding dozens in what police said was a coordinated attempt to discredit the government.

No group immediately took responsibility for the blasts, which focused on government-owned companies and public transportation.

The attacks came days before Monday’s anniversary of last year’s general election. International observers had called the balloting seriously flawed and opposition politicians have refused to take up their posts to protest what they called government rigging.

Police have blamed other small bombings in recent months on alleged militant elements of the opposition. No groups claimed responsibility for those bombings, which rarely caused injuries or significant damage. All the leaders of the main opposition parties are now in prison and standing trial for treason and genocide.