The Yemeni government apparently targeted a leading army general and rival of President Ali Abdullah Saleh by telling Saudi military commanders that his headquarters was a rebel base to be bombed.

The extraordinary plot – foiled when suspicious Saudi pilots aborted the air strike – has emerged in one of the classified US embassy cables released by WikiLeaks.

Dated February 2010, the cable illustrates the extent to which relations between Saleh and Ali Mohsen al-Ahmar had deteriorated more than a year before the general declared his support for anti-regime protesters.

The US cable recounts a meeting between James B Smith, the American ambassador in Riyadh, and Prince Khaled bin Sultan, the junior Saudi defence minister. The talks were arranged for Smith to pass on US concerns about Saudi air strikes on the Houthis, a Shia insurgent group in the north of Yemen.

Khaled told the ambassador that targets were selected by a joint committee of senior Saudi and Yemeni officers.

Smith's note continues: "Prince Khaled also reported that the Saudis had problems with some of the targeting recommendations received from the Yemeni side. For instance, there was one occasion when Saudi pilots aborted a strike, when they sensed something was wrong about the information they received from the Yemenis. It turned out that the site recommended to be hit was the headquarters of General Ali Mohsen al-Ahmar, the Yemeni northern area military commander, who is regarded as a political opponent to President Saleh. This incident prompted the Saudis to be more cautious about targeting recommendations from the Yemeni government."

Ali Mohsen was inside the headquarters at the time of the aborted attack, one of his senior aides told the Washington Post. "This was not the first attempt by the president and regime to kill him," the aide said.

Ali Mohsen, a long-time confidant of the president as well as the head of the Yemeni army in the country's north-west, was one of 11 military commanders to publicly defect last month, saying he would back "the peaceful revolution" .

For many years Ali Mohsen was Saleh's key military strongman, playing a major role in the 1994 civil war. Generally seen as the country's second most powerful man, he is usually referred to as the cousin of Saleh's two half-brothers, although some reports claim he is himself a half-brother to Saleh.

According to the cable Smith also asked Prince Khaled about evidence that some of the air strikes were hitting civilian targets, particularly a building the US believed to be a medical clinic.

The Saudi minister agreed there were problems – complaining in passing that if the US sold his country the Predator drone aircraft then targeting would be more accurate – but said the air campaign was deliberately hitting the Houthis hard to "bring them to their knees".

He added: "However, we tried very hard not to hit civilian targets," an assurance accepted by Smith.

Saudi Arabia began military operations against the Houthis in 2009 following a cross-border Houthi raid that killed two Saudi guards.