Guinea-Bissau's electoral authority on Monday rejected accusations of ballot fraud in the country's presidential elections and promised that the vote count would be transparent.
Incumbent Jose Mario Vaz's campaign team accused rivals of buying votes and stuffing ballot boxes in Sunday's elections.
Vaz has repeatedly clashed with parliament over who should lead the government, causing severe political deadlock.
The impoverished and coup-ridden West African nation went to the polls in the hope of ending the impasse.
Felisberta Vaz Moura, a spokeswoman for the National Electoral Commission, denied that there had been irregularities on Sunday.
"There was no ballot stuffing" she said, adding that the election "went well" across most of the country.
"We are determined to do everything transparently," the spokeswoman said.
Fraud was impossible because the count would be take place in the presence of candidates' representatives, she argued.
The mood was tense on voting day, which was marked by sporadic scuffles among supporters of rival political camps
Twelve candidates in total, including Vaz, are running.
Provisional election results are due by Wednesday.
A second round of voting -- planned for December 29 -- is considered highly likely given the number of candidates.
Guinea-Bissau has a long history of military coups and political assassinations since winning independence from Portugal in 1974. Vaz is the first president in 25 years to finish his term without being ousted or killed.