International observers on Thursday said Mozambique's election was conducted in an "orderly manner", but expressed concerns about voter registration irregularities and "an unlevel playing field".
The southern African country voted in presidential, parliamentary and provincial polls on Tuesday after a campaign marked by violence and claims of electoral fraud.
President Filipe Nyusi's Frelimo party -- which has ruled Mozambique since independence in 1975 -- is widely expected to again beat its civil war foe Renamo, a former rebel group turned main opposition party.
Election day was seen as largely peaceful, but tensions have risen with uncertainty over when the results will be released.
The final results must be published within 15 days of the vote, but the electoral commission has indicated a provisional tally -- which had been expected on Thursday -- would not be issued.
Ignacio Sanchez Amor, leader of the European Union's OSCE observer mission, said "voting procedures were well-implemented" on election day.
However, he said the fact that there were no observers in almost half of the country's polling stations "did not contribute to the transparency of the process".
Amor added that "an unlevel playing field was evident throughout the campaign".
"The ruling party dominated the campaign in all provinces and benefited from the advantages of incumbency, including use of state resources."
The Electoral Institute for Sustainable Democracy in Africa (EISA) said it was regrettable that irregularities in voter registration had not been addressed before the vote.
Local non-profit observer groups had reported the presence of 300,000 "ghost voters" -- names not aligned with real voters -- on the electoral roll in the southern Gaza province.
"Key aspects of the process such as the security challenges, voter registration, the campaign and selective accreditation of citizen observers posed challenges to the integrity of the elections," said EISA Mozambique head and former Ghana President John Dramani Mahama.
Former Kenyan Vice President Kalonzo Musyoka said the Commonwealth's observer mission "remained concerned about the impact" of the suspected ghost voters on the election.
However observers from the Southern African Development Community (SADC) had no such concerns.
"The pre-election and the voting phases of the 2019 electoral processes were generally peaceful and conducted in an orderly manner," said Zimbabwean Defence Minister Oppah Muchinguri-Kashiri, the SADC observer head.
The election has been seen as a key test of the peace deal sealed in August between Frelimo and Renamo, which fought a brutal 1975-1992 civil war.