African Union observers said Saturday that Togo's parliamentary elections were held in acceptable conditions despite the opposition alleging irregularities, as partial results showed the ruling party ahead.

"Despite several incidents recorded on the day of the vote, (the elections) allowed Togolese voters to express their choice in a calm and serene atmosphere," a statement from the AU's 32-member observer team said.

"As a result, the mission finds that the July 25, 2013 election was held in acceptable conditions."

Observers noted organisational issues, such as the late opening of some polling stations.

The 15-nation West African bloc ECOWAS, which sent 80 observers, had on Friday announced similar findings.

President Faure Gnassingbe's UNIR party was ahead in partial, provisional results from the electoral commission, while the Let's Save Togo coalition was the strongest opposition contender.

Let's Save Togo has alleged irregularities in connection with the vote.

Full provisional results along with a breakdown of the number of seats for each party under the proportional electoral system were expected in a day or two.

The long-delayed polls came after months of protests in the West African nation, with the opposition seeking to weaken the ruling family's decades-long grip on power.

The polls were the latest step in the impoverished country's transition to democracy after Gnassingbe Eyadema's rule from 1967 to his death in 2005, when the military installed his son as president.

Gnassingbe has since won elections in 2005 and 2010 in the country of six million people, but the opposition has denounced both as fraudulent.

His party won 50 of 81 seats in the last legislative polls in 2007, with 91 seats up for grabs this time.

Presidential polls in 2005 were marred by deadly violence, while 2007 and 2010 elections were viewed by observers as significant steps forward.