Voting stating in Tanzania's general elections widely seen as unpredictable

Tanzanians queue to cast their votes in the presidential election, at a polling station in Dar es Salaam, Tanzania Sunday, Oct. 25, 2015. Voting has started in Tanzania's general elections in which the ruling party faces a strong challenge from a united opposition. (AP Photo/Khalfan Said) (The Associated Press)

A Tanzanian man casts his vote in the presidential election at a polling station in Dar es Salaam, Tanzania Sunday, Oct. 25, 2015. Voting has started in Tanzania's general elections in which the ruling party faces a strong challenge from a united opposition. (AP Photo/Khalfan Said) (The Associated Press)

A Tanzanian woman prepares to cast her vote in the presidential election, at a polling station in Dar es Salaam, Tanzania Sunday, Oct. 25, 2015. Voting has started in Tanzania's general elections in which the ruling party faces a strong challenge from a united opposition. (AP Photo/Khalfan Said) (The Associated Press)

Voting has started in Tanzania's general elections in which the ruling party faces a strong challenge from a united opposition.

In the presidential race, the ruling party's candidate, John Magufuli, is battling former Prime Minister Edward Lowassa, who defected to the opposition earlier this year after being rejected as the ruling party's candidate.

Voters Sunday are also choosing lawmakers in the country's parliament and local officials.

The electoral commission says it hopes to announce the winning candidate within three to four days.

Damian Lubuva, the commission's head, said Saturday that a total of 23,254,485 voters are registered to vote across the East African country.

The semi-autonomous island archipelago of Zanzibar is also voting for a president and local leaders.