The United States on Tuesday called for an immediate end of violence and restraint by all sides in Yemen following a major restructuring of the country's army triggered violent clashes.

The State department urged all sides to respect the reforms by President Abdo Rabbu Masour Hadi after troops attacked the defense ministry.

"We have been urging restraint on all sides, an immediate end to the violence and respect for President Hadi and the reforms that he is putting in place and the democratic transition," State Department spokeswoman Victoria Nuland told reporters.

Troops from the elite Republican Guard, led by the son of ousted president Ali Abdullah Saleh, attacked the defense ministry's headquarters on Tuesday but were repelled.

The assault came after Hadi ordered a restructuring of the army that reduced the number of units under the command of rival chiefs, including Saleh's son.