The Ethiopian government has imposed a month-long ban on demonstrations after millions staged a huge turnout at elections.
The prime minister, Meles Zenawi, who has put himself in charge of all security forces in the capital, said tough action would be taken to head off any trouble over the results.
Millions voted in the parliamentary poll, which is expected to hand a third term to Mr Meles despite the strongest challenge ever staged by pro-free market opposition parties.
EU observers said they had no immediate word of major irregularities, but opposition groups said there had been ballot-rigging by government supporters in remote areas, which the EU failed to detect.
