Nine bombs exploded across Ethiopia's capital Friday, 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. But the bombings could point to growing militant opposition to the government. The attacks came days before anniversary Monday 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. "This is just a futile attempt to (give) the impression that there is no peace or tranquility in the city," federal police spokesman Commander Demsash Hailu said, reading a government statement. "However, it is evident that the people of Addis Ababa, as usual, are leading their lives."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. In the past, other groups such as Oromo Liberation Front and the Ogaden National Liberation Front, both fighting for greater autonomy for their regions, have claimed responsibility for attacks outside Addis Ababa. Agents from neighboring Eritrea are also frequently blamed.