The Democratic Republic of Congo's security forces detained a U.S. diplomat Sunday in a raid that also targeted journalists and regional democracy activists and accused them of posing a threat to stability, a government spokesman said.

The diplomat "was found among a group of people that was believed to be in the process of bringing an attack against state security," Lambert Mende said. He did not disclose the diplomat's name or position.

The U.S. Embassy in Kinshasa did not respond to messages seeking comment. The State Department did not offer additional information when contacted Sunday night.

The detentions followed a news conference in Kinshasa organized in support of a Congolese movement known as Filimbi that aims for greater youth participation in politics.

Mende did not say how many people were detained. He said the group was held for identification and investigation, and that foreign journalists had been released. He did not have information on whether the diplomat, activists or local journalists had been released.

The activists included members of Burkina Faso's Balai Citoyen and Senegal's Y'en a Marre movements. Both have led large-scale protests in recent years against presidents attempting to extend their time in office.

In 2011 and 2012, Y'en a Marre mobilized against the re-election bid of Senegal's then-President Abdoulaye Wade, who ultimately lost to current President Macky Sall. Balai Citoyen proved instrumental in the popular uprising that led to Burkina Faso ex-President Blaise Compaore's fall from power in October after 27 years in office.

Balai Citoyen leader Serge Bambara speculated that the detentions could be linked to the "current political situation" in the Democratic Republic of Congo.

In January, mass protests erupted against proposed changes to the electoral law that were widely seen as an attempt by President Joseph Kabila to prolong his time in power. Human Rights Watch reported that at least 40 people were killed in Kinshasa and the eastern city of Goma.