RIYADH: Saudi Arabia on Saturday executed three soldiers for "high treason", the defence ministry said, in a rare public announcement that accused them of colluding with an unspecified enemy.

The executions come as a Saudi-led military campaign intensifies in neighbouring Yemen and Crown Prince Mohammed bin Salman, the kingdom's de facto ruler, consolidates his grip on power.

The soldiers were convicted of "the crime of high treason in cooperation with the enemy" in a way that threatens the kingdom and its military interests, the ministry said in a statement carried by the official Saudi Press Agency.

The statement named the three soldiers -- Mohammed bin Ahmed, Shaher bin Issa and Hamoud bin Ibrahim -- without identifying which enemy they were accused of aiding.

Saudi Arabia, a Sunni powerhouse, views Shiite Iran as its main regional foe and identifies Yemen's Tehran-aligned Huthi rebels as a major security threat to the oil-rich kingdom.

The statement makes a rare announcement of military executions in the kingdom, which is known to be highly secretive about its armed forces.

"The fact that the names of the decedents were publicised means the Saudis must consider their alleged misconduct to be exceptionally egregious and thus worthy of exemplary punishment," David Des Roches, from the Near East South Asia Center for Strategic Studies in Washington, told AFP.

The defence ministry said the soldiers were executed in the military's Southern Command, based close to the border with Yemen, where Saudi Arabia is leading a six-year campaign against Huthi rebels.

Riyadh led a military coalition into Yemen in March 2015 to prop up the internationally recognised government, but it has struggled to oust the Huthis.