Violence and delays are marking the hours before Saturday's (today's) presidential vote in Nigeria. Militant leaders in the oil-rich but restive south are vowing to disrupt the process. VOA's Nico Colombant reports from Abuja.

Heavy gunfire broke out late Friday in many parts of the capital of Bayelsa state, Yenagoa, including at a hotel where the governor of the state and ruling party vice presidential candidate, Goodluck Jonathan, is staying.

His aides say he escaped unharmed and that he was taken to a safe location

Witnesses said a police office, electoral offices and government buildings were also attacked.

Ethnic Ijaw militants in the state have said they were angry at the alleged massive fraud that took place during last week's state elections. They also said many polling centers in ethnic Ijaw areas never opened.

The militants say they are fighting for a more equitable share of oil wealth.

An election observer with the Abuja-based Center for Democracy and Development, John Ikubaje, says poor preparations and woeful security are endangering the credibility of the vote. "We believe that the security must ensure that the people's vote is well protected. That is what we really want. Without doing that during the presidential election, we believe that at the end of the day, people will just vote and their vote will not count -- and I repeat that again -- their vote will not count," he said.

The opening of the polls has been delayed until ten in the morning, as ballots had to be flown from overseas to include a reinstated presidential candidate, controversial Vice President Atiku Abubakar.

Some observers said they were worried when the ballots would arrive at remote polling centers.

If voting does take place, the front-runners in a crowded field are the ruling party's candidate, Umaru Musa Yar'Adua, and former military ruler, Muhammadu Buhari.

Information Minister Frank Nweke says Nigeria is doing the best it can in difficult conditions. "The federal government calls on all Nigerians to keep faith with our hard won democracy, and we also want to call on our international friends to ensure that democratic culture evolves in Nigeria, in the same way and manner it evolved in their respective countries through years of practice," he said.

A European Union observer said given the current circumstances it is highly unlikely the poll can be credible.

Elections are also scheduled for a new parliament. The previous assembly rejected proposals to allow outgoing President Olusegun Obasanjo to seek a third elected term.