Two of those arrested during raids concentrated in Brussels and Antwerp were Tunisians, three were Moroccans and the rest were Belgian nationals, the spokesman said on Wednesday.
"So far we have arrested 14 people. We are making further searches this morning," he added.
The 38-year-old woman blew herself up a few weeks ago in what security sources believe could be the first attack in Iraq involving a European woman.
She has not been identified, but officials say she was born in Belgium of European origin and converted to Islam after marrying a Muslim.
Asked if those arrested included members of the woman's family, the police spokesman replied: "It's not a family case."
"We know these groups are always planning attacks ... What we can say is there were no attacks planned in Europe," he added.
De Standaard newspaper earlier quoted a US official in Iraq as saying the attack was carried out on 9 November and targeted a US military convoy south of Baghdad. No one was killed apart from the woman herself, it reported.
It added a Belgian passport was found on her body, along with papers which showed she had entered Iraq via Turkey.
"We know these groups are always planning attacks ... What we can say is there were no attacks planned in Europe"
Belgium, home to the European Union institutions and Nato, has suffered no attacks on its soil by Islamic fighters.
The country has large Arab and Muslim communities in some of its cities and is thought to have been used as a rear base for Islamic fighters involved in terror plots.
Earlier this month, 13 men accused of belonging to an Islamic group blamed for bombings in Madrid and Casablanca went on trial in Brussels.
They face charges of providing false papers, safe houses and logistical help to members of the Moroccan Islamic Combatant Group (GICM), which is held responsible for the 2004 Madrid attacks on four commuter trains that killed 191 people.
The GICM has also been linked to the 2003 bombings in Casablanca, which killed 45 people including 12 bombers. Among those accused is Khalid Bouloudo, an alleged leader of the GICM's Belgian cell.