By Bienvenu-Marie Bkumanya and Aaron Ross
KINSHASA (Reuters) - Security forces in Democratic Republic of Congo arrested a U.S. diplomat along with pro-democracy activists, journalists and musicians on Sunday following a news conference in the capital Kinshasa, a government spokesman and witnesses said.
The event was held by activists from Congo, Senegal and Burkina Faso at a cultural center and was attended by around 20 journalists and observers.
Around a dozen soldiers, both in uniform and civilian clothes, entered the hall as the news conference finished and began making arrests, a Reuters witness said, adding that some attendees were assaulted during the raid.
The soldiers also arrested the French owner of the center and more than a dozen musicians waiting outside the hall to perform. In total around 40 people were detained, the witness said.
"Some say that it was a press conference - an exchange between the members of the Burkinabe and Senegalese civil societies and the Congolese civil society," Information Minister Lambert Mende told Reuters.
"The (intelligence) services believe, however, that it was a project organized by those who identify (themselves) as instructors in insurrection," he said, confirming the arrests, including that of the diplomat.
The U.S. embassy in Kinshasa declined to immediately comment on the events.
Mende denied that soldiers had been involved in the raid and said the arrests had been made by police. Those detained were taken to holding facilities run by the national intelligence service and police, and an investigation was under way, he said.
By early evening, all four detained foreign journalists had been freed, several of the released reporters said, however a Congolese journalist and the U.S. diplomat were among those still in custody.
Congolese President Joseph Kabila is constitutionally required to leave office in December 2016 at the end of his second elected term but critics accuse him of trying to extend his time in office.
At least 40 people were killed in violent protests in January against a revision of the country's electoral law that opponents said was meant to delay the polls.
The arrested activists included Fadel Barro, a member of the Senegalese collective of hip-hop artists "Y en a Marre", which helped organize protests against former President Abdoulaye Wade's bid for a third term in 2012.
A member of the grassroots political group "Balai Citoyen", which played a leading role protests that toppled longtime Burkina Faso President Blaise Compaore last year, was also detained.
(Writing by Aaron Ross; Editing by Joe Bavier and Alison Williams)