GUÉDIAWAYE, Senegal — Raids for suspects in the Paris attacks flashed across the television at the Sow family house in this small village along Senegal’s coastline.

The news reports from France served as a backdrop to an international hunt for extremists that now, surprisingly, has reached the living room of Marieme Sow, thousands of miles away in a country long held up as a model of an Islamic democratic society.

Ms. Sow has been accused of helping support the activities of Boko Haram, the group that pledged loyalty to the Islamic State after unleashing years of violence in Nigeria and its neighboring countries.

She was part of a Senegalese sweep in recent weeks of people suspected of having close ties to Boko Haram or radical Islamist ideologies, including four imams and other suspects who were jailed on charges of advocating terrorism.