Polls have closed in Tanzania’s presidential and parliamentary elections, with the ruling party facing its toughest test yet from opposition rivals led by former Prime Minister Edward Lowassa.

In the lead-up to Sunday’s polls, opposition leader Lowassa tapped into mounting anger over corruption and the slow pace of change in East Africa’s second most populous country. With its 54-year rule, the Party of the Revolution (CCM) is the dominant party in Tanzania and the longest reigning ruling party in Africa.

However, CCM has faced growing pressure to speed up development of Tanzania’s significant natural gas resources to spur economic growth and lower stubbornly high poverty rates.

Al Jazeera’s Catherine Soi, reporting from Tanzania’s commercial capital, Dar es Salam, said polling stations opened early to allow the stream of voters who want to cast their ballot before the major crowds turn out. “People have been coming since very early in the morning. They just want to vote early so they can go home and go about their business and wait for the result,” Soi said.

“Things are smooth and people are patiently waiting to cast their vote. They want free and fair elections.” There are more than 63,000 polling stations in Tanzania, and each station is only allowed 450 voters. “This is to quicken the process.” Soi added.