Ivorian domestic intelligence agents on Saturday detained former minister Alphonse Douati, a top figure in ex-president Laurent Gbagbo's party, hours after an attack on its offices, officials said.
Douati, who is deputy secretary general of the Ivorian Popular Front, was "detained for questioning by DST agents at his home and taken to" agency offices, FPI spokesman Mamadou Franck Bamba told AFP.
The reason for the arrest was not immediately known.
Armed men earlier attacked Gbagbo's party headquarters, abducting two people and wounding three, the party said, blaming the raid on supporters of President Alassane Ouattara.
The incident, in which Ouattara's party denied involvement, heightened tensions in the country's economic capital of Abidjan after a recent series of attacks against the army that the government has blamed on Gbagbo's FPI.
Ouattara was Gbagbo's rival in a post-election crisis that plunged the country into chaos from December 2010 to April 2011 and claimed 3,000 lives.
Police and troops of the UN peacekeeping mission in Ivory Coast, known as ONUCI, went to the scene after the attack.
ONUCI called on the government to find and punish those responsible and made an "urgent appeal for calm" and national reconciliation.
It was the latest incident to affect Abidjan more than a year after the post-electoral crisis sparked by Gbagbo's refusal to step down despite having lost presidential elections to Ouattara.
On Thursday, armed men attacked an army base, a prison and police stations near Abidjan, prompting Prime Minister Jeannot Kouadio Ahoussou to call on those responsible to disarm and not block the country's "revival."
Ahoussou called for dialogue and announced the dispatch of teams to listen to the population's grievances across the country.
ONUCI says the violence demonstrates the need to continue the demobilisation, disarmament and integration of militias and others responsible for the post-election violence.
The UN mission said at least 70 people had been arrested in the past few days on suspicion of attempting attacks on the state.
Five months of unrest followed the disputed polls before Gbagbo was eventually arrested when forces loyal to Ouattara stormed his heavily fortified home with French and UN military backing.
He was extradited in November to The Hague, where he faces charges of crimes against humanity at the International Criminal Court.