RIYADH - Yemeni Shi'ite rebels handed over two captive Saudi soldiers via Yemeni authorities on Thursday as part of efforts to end a long-running conflict in northern provinces bordering Saudi Arabia, a government official said. A Saudi defence ministry spokesman said the two men "were exhausted but in decent shape. Assistant Defence Minister Prince Khaled bin Sultan welcomed them at Riyadh's military base." Riyadh, sucked into the fighting with rebels in November, had said returning the soldiers would help prove their captors were serious about ending their conflict with Saudi Arabia. "We don't know anything about the two remaining (Saudi) prisoners. We will not rest until we recover them," the spokesman said. The Houthi insurgents, named after their leader Abdul-Malik al-Houthi, offered Riyadh a truce last month and released one Saudi soldier earlier this week. The Saudi Interior Ministry is holding 500 "infiltrators", the Saudi spokesman said, without giving details. "They are treated according to international laws," he said. A former Yemeni prime minister, Haidar al-Attas, who lives in Saudi Arabia, mediated a deal under which the Houthis would hand over the Saudi soldiers to the Yemeni government, a source close to the talks said. Under the agreement, the Saudis would also hand over rebel prisoners to the Yemeni government. The Saudi spokesman declined to say when Saudi Arabia would start handing over Yemeni prisoners. He noted however that the Yemeni army had started taking positions along the border. "We are monitoring the situation."