* Saudis had assured only rebel targets hit--U.S. cable
* Border war with Yemeni rebels ended with February truce
RIYADH, Dec 8 (Reuters) - Saudi armed forces killed Yemeni civilians when fighting Shi'ite rebels in a brief border war despite assurances that only rebel targets were hit, leaked U.S. diplomatic cables quoted a Saudi official as saying.
Top oil exporter Saudi Arabia fought Yemeni rebels for several months in a border war that ended with a ceasefire in February.
In public statements during the fighting, Saudi Arabia said that only rebel positions in the border area were attacked. But the leaked cables suggest civilians died.
"We tried very hard not to hit civilian targets," Prince Khaled bin Sultan, son of Crown Prince Sultan bin Abdulaziz, told the U.S. ambassador in Riyadh, according to the cable from the Riyadh embassy in February.
"Obviously some civilians died, though we wish that this did not happen," the prince, who is also assistant defence minister, said in the meeting requested by the ambassador to relay U.S. concerns about civilian casualties in the conflict.
Prince Khaled confirmed that Saudi forces hit a building the United States believed to be a clinic but the Saudis thought it was being used as a base by rebels.
He also said the Yemeni military had helped recommend rebel targets, the cable said. Riyadh denied at the time that it was offering military aid and said it acted in self-defence after border positions had been attacked by the Shi'ite rebels.
But some Yemeni intelligence had been poor, with a Saudi fighter pilot aborting a sortie after sensing something was wrong, the cable reported. It said the target turned out to be the headquarters of a Yemeni military commander.
Saudi Arabia is Yemen's biggest donor and very worried al Qaeda will exploit instability in the poor southern neighbour.
(Reporting by Ulf Laessing; editing by Mark Heinrich)
Our Standards: The Thomson Reuters Trust Principles.