JIZAN: Saudi forces battled Yemeni rebels on the oil kingpin's border with its impoverished neighbour, both sides said on Saturday, with the rebels claiming to have captured Saudi ground troops inside Yemeni territory.

The Saudi military pounded rebel positions on Jebel al-Dukhan, a 2,000-metre (6,600-foot) peak on the frontier, with air strikes and mortar fire overnight, the kingdom's Jazannews.com news website reported.

The bombardment killed a number of rebels who the website said were "infiltrators" in Saudi territory.

Some 40 Yemeni rebels surrendered to Saudi forces, the website added, citing witnesses.

Saudi media said that fighting erupted on Friday night in the Saudi border villages of al-Qarn, Qawa, and al-Dafeneyah, after the rebels infiltrated the area dressed as women.

The rebels in turn said that they had come under attack by Saudi ground troops inside Yemeni territory. They said they had repulsed the cross-border assault, capturing a number of soldiers.

"With Allah's help, the Saudi tyrannical advance into Yemen's territory has been defeated," the rebels said on their website. "A number of its troops have been captured and several military vehicles and supplies been seized."

The Saudi air force struck the border zone on Wednesday and Thursday to "neutralise the firing by intruders" and to clear areas where they had encroached on the kingdom's territory, the government said on Thursday.

It said the strikes were in response to an incursion on Tuesday in which the rebels attacked a border post, killing one Saudi border guard and wounding 11.

Saudi media said four women civilians were also killed in rebel shelling. They were all from the same family, the reports said.

Saudi authorities have evacuated residents of border villages to newly erected camps.

A Saudi government adviser told AFP on Thursday that F-15 and Tornado jets had bombed rebel camps inside Yemen, although official announcements have insisted the strikes were all inside the kingdom.

He said the action was taken with Sanaa's blessing.

The adviser's comments were the first acknowledgement of Saudi involvement in the Yemeni government's efforts to put an end to the five-year-old uprising by Zaidi Shiite rebels in the mountainous north of the country, one of the world's poorest.

On Wednesday, a Sanaa spokesman denied any Saudi military action against Yemeni villages.

Washington has voiced concern over the expansion of the conflict to involve its key Gulf ally.

"It's our view that there can be no long-term military solution to the conflict between the Yemeni government and the rebels," State Department spokesman Ian Kelly said on Thursday.

Yemeni authorities accuse the rebels of seeking to restore the Zaidi imamate that ruled in Sanaa until its overthrow in a republican coup in 1962 that sparked eight years of civil war. The rebels deny the charge.

An offshoot of Shiite Islam, the Zaidis form the majority community in the far north but are a minority in mainly Sunni Yemen.

Yemeni President Ali Abdullah Saleh is himself a Zaidi.