Opposition supporters protested in Zambia's capital as President Levy Mwanawasa widened his lead in the presidential election and a main challenger made accusations of ballot-rigging.
Police fired tear gas at demonstrators Sunday outside the main vote-counting center in Lusaka, a stronghold for opposition leader Michael Sata. Numerous protesters have been arrested.
Mr. Sata says there were irregularities in Thursday's election.
The electoral commission says Mr. Mwanawasa has 39 percent of the votes counted so far, while United Democratic Alliance leader Hichilema Haikande has 30 percent.
Mr. Sata has 28 percent. He had been seen as the main challenger and held an early lead in the voting.
The opposition leader says more than 400,000 ballots are missing. He says there will be "severe consequences" if the electoral commission does not verify the missing votes before declaring a winner.
Some information for this report was provided by AP and Reuters.