Updated

Yemen's new president faced a new challenge Sunday when the powerful son of the man he replaced appointed his own person — a relative — to head a security unit to protect his father.

One of President Abed Rabbo Mansour Hadi's main goals has been to purge the military of his predecessor's cronies and relatives to enable reforms and restore security to the country in turmoil for more than a year.

These steps are seen essential to enable Yemen's armed forces to confront al-Qaida-linked militants, who have taken over parts of southern Yemen while the country has been distracted by the power struggle in the capital.

A senior military official in the Defense Ministry said former president Ali Abdullah Saleh continues to meddle in the country's affairs.

Ahmed Ali Abdullah Saleh, son of the former president, commands the powerful Special Forces and Republican Guard, among the country's best trained troops. His appointment of a relative, Tarek Mohammed, to head his father's security unit was direct insubordination to Hadi.

Hadi had already demoted Mohammed from head of the Presidential Guards to head a provincial military unit, an order Mohammed and the younger Saleh refused to obey.

The military official said Hadi has rejected the new appointment. In response, Mohammed refused to hand over his current job during a meeting attended by the U.N. representative to Yemen.

The official was speaking on condition of anonymity because he was not authorized to speak to the media.

Another relative rejected an order to resign as head of the air force for weeks, finally stepping down last week. That dispute forced a shutdown in Yemen's commercial airport for a day.

Hadi took over from Saleh in February following nearly a year of street protests. In his purge efforts, he faces the risk that his predecessor's loyalists might cause massive disruptions rather than go quietly.

Earlier this month, the ex-president Saleh said in a statement that his loyalists should maintain leading roles in running the country's affairs to ensure stability, in clear defiance against attempts by his successor to purge them.

The ongoing power struggle could hamper the new government's offensive against al-Qaida militants. In recent weeks, troops have been engaged in daily battles with the militant group in southern Yemeni provinces.

Also Sunday, Yemeni security officials said three suspected al-Qaida militants were killed when a missile hit their SUV in northeastern Yemen. The officials had no details on the source of the attack or the identity of the three. U.S. drones have been active over Yemen, tracking and striking al-Qaida operatives with missiles.

The officials spoke on condition of anonymity because they were not authorized to brief reporters.

The militant group said Sunday it released 73 soldiers captured by its fighters during battles with government forces in the south.

The terror network said in an emailed statement that the freeing of the soldiers followed mediation efforts by tribal elders and senior clerics. Relatives of some freed prisoners confirmed the release.

The soldiers were freed in the city of Jaar in the southern province of Abyan in a ceremony attended by top leaders of the terror network in Yemen, including military leader Qasim al-Rimi, witnesses and the statement said. The soldiers left in trucks and private cars for the nearby port city of Aden.

Al-Qaida has held Jaar for a year. The province's capital Zinjibar is also under al-Qaida control, but government troops fought their way into its center last week.