RIYADH: Saudi jets pounded Shiite rebel camps inside Yemen on Thursday and ground troops could move across the border against them after they killed a Saudi border guard, an informed Saudi source told AFP. F-15 and Tornado jets have been bombing the positions of the Zaidi Shiite rebels near the border with southern Jizan province since Tuesday, the source said. “They’ve been hit hard and it’s ongoing,” he told AFP. “This is not a hit and run, this is a sustained action” that could involve a ground incursion into Yemen to “clean out” the rebel camps in coordination with Yemen authorities, he said. The assault was launched after a small group of Zaidi militants entered Saudi territory Tuesday in the rugged Jebel al-Dukhan area and occupied two small frontier villages before being driven out by Saudi troops.