An opposition official says more than two dozen supporters who were detained in Gabon after election results were announced have been released.

Paul-Marie Gondjout with the National Union opposition party said late Friday the 27 people blocked inside the opposition candidate's campaign headquarters by security forces were allowed to leave after more than 24 hours.

Their candidate, Jean Ping, has claimed election fraud after narrowly finishing second. Election officials say the vote was won by incumbent President Ali Bongo Ondimba, whose father had ruled the country since the 1960s.

Ping's supporters have taken to the streets in protest, and at least three people have been killed.

A government spokesman has said security forces seized Ping's headquarters with the 27 people inside because the protests allegedly were being planned there.