Authorities in southern Yemen have closed the country's second-largest airport there in protest over the Shiite rebels' power grab in the capital, Sanaa, which has plunged the nation deeper into chaos and threatens to fracture the country.

Airport chief in the port city of Aden, Tarek Abdu, says the shutdown went into effect at 7 a.m. Wednesday and would last "until further notice," following orders from the governor. Local authorities also closed the port, a major hub in the Gulf of Aden.

The development came after Shiite rebels known as the Houthis took over the presidential palace in Sanaa on Tuesday and shelled the residence of President Abed Rabbo Mansour Hadi. The president was unharmed.

Aden's top security committee denounced the Houthis' attacks as a "coup" against "national sovereignty."