The party of Kenya's opposition challenger Raila Odinga says he has won his country's presidential election.
Official figures gave Mr Odinga a four percentage point lead over President Mwai Kibaki, with three-quarters of the vote counted.
President Kibaki's party scoffed at the claims, saying it would wait for the official results.
"Any other kangaroo results given by any Tom, Dick or Harry deserve every contempt," said a spokesman.
The head of the country's election commission, Samuel Kivuitu, said that with 159 of Kenya's 210 constituencies tallied, Mr Odinga had 3,726,240 votes, to Mr Kibaki's 3,416,139 - around 49.5% to the challenger and 45.3% to the president.
Mr Kivuitu admitted there had been problems establishing results from some areas.
He warned that "if we don't get the results quickly, we will have to announce what we have".
Mr Odinga's Orange Democratic Movement raised fears that the delay may indicate electoral officials were under pressure to rig the result, and said it was now time for the president to admit defeat.
"In view of the growing anxiety and restlessness in the country over the extended delay... we now call upon the outgoing president to acknowledge and respect the will of the Kenyan people and concede defeat," said Mr Odinga's vice-presidential candidate Musalia Mudavadi.