Egyptian election officials are expected late Monday to announce results from the first round of presidential elections, confirming a polarizing runoff between the Islamist Muslim Brotherhood's candidate and another with strong ties to former President Hosni Mubarak's regime.

The preliminary counts from Egypt's first free presidential race last week show the Brotherhood's Mohammed Morsi in the lead and former prime minister and secularist Ahmed Shafiq a strong second.

The runoff, to be held on June 16-17, would offer Egyptians a stark choice between candidates from divergent paths.

Morsi received about 25 percent of the vote, according to preliminary results. He was not his Islamist group's first choice for its presidential candidate. But he got the job when the Brotherhood's lead candidate was disqualified and then became a front runner in a show of the group's political muscle.

During the campaign, Morsi delivered fiery speeches and vowed his presidency would be based on Islam but not be a theocracy.

Shafiq was Mubarak's last prime minister before he lost power in last year's pro-democracy protests.

The former Air Force commander was appointed prime minister in hopes of appeasing the popular revolt. But because of that connection to Mr. Mubarak, he is viewed with some suspicion by activists involved in the 2011 movement and polarized voters.

A victory for one of the secularist candidates would mark a significant turn from parliamentary elections just six months ago when more than 70 percent of voters cast ballots for Islamist parties.

But already results are being contested. The expected three top candidates have filed appeals with the election commission, alleging violations and fraud.

The third place finisher in preliminary results, socialist Hamdeen Sabahi, called for a partial vote recount in five provinces where the results are in dispute.