A Houthi militiaman looks on as he stands at the yard of the Republican Palace in Sanaa on Wednesday. Armed men from Yemen's newly dominant Houthi group took over a special forces army base in the capital Sanaa early on Wednesday, soldiers there said.

AFP/Sanaa

Efforts intensified on Wednesday to find a French woman and her Yemeni interpreter kidnapped in crisis-hit Yemen, with relatives reaching out to tribal chiefs and the Shia militia that controls the capital.

Unidentified gunmen seized 30-year-old Isabelle Prime - a consultant working on a World Bank-funded project - and Sherine Makkaoui from a car in Sanaa on Tuesday.

French Foreign Minister Laurent Fabius said Paris was making "every effort" to reach Prime's kidnappers, while her employer said "some contact" had been made with them.

The abduction has prompted calls by France for its nationals to avoid the impoverished Gulf nation following months of unrest.

"We contacted various tribal leaders in Sanaa and in the provinces of Jawf and Marib to ensure their cooperation for the release of the two women," Yassine Makkaoui, uncle of the Yemeni woman, told AFP.

"We have also contacted, for the same reason, the interior ministry and the Houthis," he added.

Kidnappings are common in Yemen, where security has significantly worsened since the Houthis - also known as Ansarullah - swept into Sanaa unopposed in September.

After the Houthis' attempts to expand into southern and central Yemen were checked by fierce resistance from Al-Qaeda and from Sunni tribesmen, the militia moved to take power this month in what Yemen's Gulf neighbours branded a coup.

Lack of security

Makkaoui blamed the militia for the lack of security in the capital that allowed his niece and Prime to be abducted.

"The kidnapping took place in broad daylight in the centre of Sanaa where the Houthis are responsible for maintaining order," Makkaoui said.

"They control both the ministries of defence and interior, and we hold them responsible" for the women's fate, he added.

Prime and Makkaoui were seized after their car was stopped by men dressed as police officers, according to her employer, Ayala Consulting.

"There has been some contact" with the kidnappers, Francisco Ayala, president of the consulting firm based in Miami and Ecuador, told AFP.

Western nations including Britain, France and the US closed their embassies in Yemen this month over security concerns and have also called on their citizens to leave.

On Wednesday, France's Fabius repeated an earlier request that "all nationals immediately leave Yemen".

Militants have abducted Westerners in Yemen in the past, and a US photojournalist and a South African teacher held by Al-Qaeda were killed during a failed US rescue mission in December.

Successive challenges

Yemen, long on the front line in the fight against Al-Qaeda, has been wracked by violence since the ouster of longtime autocrat Ali Abdullah Saleh in February 2012 following a year-long popular uprising.

Saleh's successor Abedrabbo Mansour Hadi faced successive challenges, including waves of Al-Qaeda attacks on security forces and increasingly forceful calls for southern autonomy, or even secession.

The Houthis surrounded the president's residence in January, prompting Hadi and Prime Minister Khalid Bahah to tender their resignations.

Hadi reversed his decision on Tuesday after escaping house arrest in Sanaa, staking a claim to lead the country out of crisis.

He resurfaced in Aden, capital of the formerly independent south Yemen, but Bahah remains under house arrest in Sanaa along with other ministers and officials.