U.S. security officials say they have seen an uptick in extremist threats against targets in New York as the city battles the pandemic. (Frank Franklin II/AP)

Extreme right-wing organizations and radical Islamist groups are seizing on the turmoil and panic created by the coronavirus pandemic to advance their violent agendas, often using similar tactics and the same messaging apps, security officials and experts say.

In recent weeks, racist and anti-Semitic organizations, as well as the Islamic State, al-Qaeda and radical Shiite networks, have ramped up recruitment efforts, encouraged attacks and advanced hate-filled conspiracy theories about the novel coronavirus.