Iran-backed Shiite rebels in Yemen called on supporters to battle forces loyal to the embattled U.S.-backed Yemeni president as the last remaining American troops evacuated the country.

The State Department revealed that the U.S. military has withdrawn its remaining personnel out of Yemen due to a deteriorating security situation.

Citing unnamed sources in the region, CNN reported that the evacuation involved nearly 100 Special Operations forces from the Al Anad airbase, including Navy SEALs and members of the Army’s Delta Force.

Rather than an evacuation, the State Department called it a relocation of U.S. forces out of Yemen.

We “continue to actively monitor terrorist threats emanating from Yemen and have capabilities postured in the area to address them,” declared Jeff Rathke, a State Department spokesman, late on Saturday. “As we have in the past, we will take action to disrupt continuing, imminent threats to the United States and our citizens.”

The Associated Press (AP) reported that on Saturday Houthi rebels issued a statement announcing their offensive against security and military forces loyal to U.S.-backed Yemeni President Abed Rabbo Mansour Hadi, calling it a fight against extremists.

Houthis, members of the Shiite Zaydi sect, represent close to 30 percent of Yemen’s population, noted AP.

Yemeni President Hadi and the U.S. intelligence community have linked the Houthi rebels to Iran, something the group denies.

Houthis now reportedly control the Yemeni capital Sanaa and nine of the country’s 21 provinces.

The U.S. closed its embassy in Yemen last month. Houthi rebels seized the presidential palace in the Yemeni capital Sanaa late in January.

The Pentagon repeatedly told Breitbart News that it had retained its capabilities to conduct counter-terrorism operations in Yemen after the Houthi rebels took over the capital in Yemen.

Al-Qaeda in the Arabian Peninsula (AQAP) is based in Yemen. U.S. military advisers were helping their Yemeni counterparts combat AQAP through drone strikes and logistical support.

The U.S. continues to support President Hadi, mentioned the State Department on Saturday.

According to the U.S. intelligence community’s World Wide Threat Assessment released late last month, the Shiite Houthi “ascendency in Yemen has increased Iran’s influence as well.”

Houthi rebels are facing resistance from Sunni AQAP, which the intelligence assessment added, “has taken advantage of many Sunni tribes’ opposition to [Houthi] expansion to gain recruits to fight against the [Houthis].

The Islamic State (ISIS/ISIL), also a Sunni group, is also now reportedly operating in Yemen.

ISIS took responsibility for the March 20 coordinated suicide bomb attack on two Shiite mosques in Sanaa that killed at least 137 people, including women and children.

The Sunni extremist group was targeting members of the Shiite Houthi tribe.

“We are concerned that the well-being of all Yemenis now stands threatened by increasing instability, with extremists trying to capitalize on growing volatility as witnessed in the unconscionable March 20 attacks that killed over 130 Yemeni men, women, and children,” noted the State Department spokesman.