SAN'A, Yemen (AP) - Saudi Arabian forces seized a strategic mountain straddling the border with Yemen and cleared it of Shiite rebels after five days of fighting that have left three Saudi soldiers dead, a Saudi defense official said Sunday.

Meanwhile, rebels said they shot down a Yemeni fighter jet. While Yemen acknowledged the crash, it attributed it to a "technical error."

Saudi forces began shelling and bombing rebel positions last week, dramatically escalating a five-year conflict between Yemen's weak central government and rebels in the north of the impoverished country.

The Saudi government cooperates with Yemen to fight the Shiite rebels, known as Hawthis, out of fears that extremism and instability in Yemen could spill into its country, the world's largest oil exporter.

Assistant Saudi Defense Minister Khaled Bin Sultan said Sunday's advance was a step toward sealing the Saudi border against the rebels.

"All the mountain slopes inside the Saudi border have been cleared," he said, according to the official Saudi Press Agency.

Saudi forces were still trying to stop rebel infiltrators elsewhere, he said.

Saudi-owned Al-Arabiya TV aired footage of Saudi soldiers capturing and blindfolding men in traditional Arab robes whom the station identified as Hawthi fighters.

Among the areas Bin Sultan said Saudi forces seized was Dokhan mountain, a strategic high point in the rugged border region, where rebels seized a Yemeni army base last month. The mountaintop gives commanding views of Saudi border installations and other military sites in the kingdom.

Saudi officials say their military has fought only in its own territory, focusing on rebel infiltrators, but Yemeni rebels, military officials and Arab diplomats say Saudi strikes have hit deep inside northern Yemen.

Yemeni President Ali Abdullah Saleh vowed on Saturday to quash the rebels.

Rebel spokesman Mohammed Abdel-Salam denied that rebels had crossed the Saudi border, saying those detained were Yemeni migrants hoping to work in the much richer country.

He said the "lies" about rebel infiltrators "reveal the failure of Yemeni government in confronting our forces, and that has pushed the Yemeni regime to seek help from the Saudis."

Abdel-Salam also said rebel fighters shot down a Yemeni fighter jet on Sunday, and that both Yemeni and Saudi jets have carried out continuous strikes in the region, "damaging many villages and killing civilians."

A Yemeni defense official said one of its Sukhoi jets crashed on Sunday near the Saudi border due to a technical error.

He spoke on condition of anonymity because he was not authorized to speak to the press.

The rebels also sent footage to the Associated Press showing fighters dancing on an army truck carrying a heavy machine gun that appeared to have belonged to Saudi border guards.

The Shiite rebels claim the needs of their communities are ignored by a Yemeni government that is increasingly allied with hard-line Sunni fundamentalists, who consider Shiites heretics.

Besides the northern rebels, Yemen's government is also confronting a separatist movement in the south and a lingering threat from al-Qaida militants.

Yemen, the ancestral homeland of Osama bin Laden, has cooperated with the U.S. in fighting terrorism but has struggled to confront Islamic extremists.