The Houthi militants who ousted Yemen's transition government are detaining several US nationals inside a prison in the capital city of Sanaa, US media reported on Sunday quoting officials from the department of state.
The Houthi militant group has not commented on the reports coinciding with talks by US and Houthi officials in Oman.
The talks are being focused on the current crisis in Yemen.
After tightening their grip on power early this year, the Houthis forced all foreign missions to shut down in Yemen.
Today, the UN envoy to Yemen Ismail Ould Cheikh arrived in Saudi Arabia for a meeting with president Abd Rabbuh Mansour Hadi after a short visit to Yemen.
Cheikh is meeting with the Yemeni government and factions in an effort to bring all to the Geneva talks on the crisis.
Hadi and the government including Vice President Khalid Bahah have been acting from Riyadh for around two months.
They travelled to Saudi Arabia after they fled house arrest by the Houthis who ousted them in September.
Lately, Hadi affirmed they will come back to resume their duties from Yemen as Saudi-led airstrikes against the Houthis are continuing. The airstrikes were launched on March 26.