SAUDI ARABIA. Saudi jets and ground forces blasted Yemen rebel positions along the two countries' rugged frontier to "neutralise" infiltrators who had crossed over and killed a Saudi border guard, Riyadh said on Friday.
The air strikes from southern Jizan province were to "neutralise the firing by intruders" and to clear areas where they had encroached on Saudi territory, the government said in a statement on the official SPA news agency.
Earlier, a government advisor said Saudi F-15 and Tornado jets had bombed camps of the Zaidi rebels inside Yemeni territory on Wednesday and Thursday in response to a rebel attack on a border post a day earlier in which one Saudi was killed and 11 wounded.
"They've been hit hard and it's ongoing," the advisor told AFP, adding that the move was taken with the knowledge of the Yemeni government.
The Saudi government did not acknowledge air strikes or reported shelling inside Yemen territory, and Yemeni officials denied knowledge of any Saudi attacks inside its territory.
The SPA statement said government forces had attacked rebel positions "inside Saudi territory" around the 2,000 metre (6,600 foot) Jebel al-Dukhan mountain which straddles the border of Yemen and Saudi Arabia's Jizan province.
But according to the government adviser, the attacks included going after rebel encampments in the area of Saada, a rebel stronghold province over the border.
"We took back a small piece of territory and hit their camps around Saada," he said.
The rebels also said that Saudi air force jets had attacked them inside Yemeni territory.
The Saudis said they took action following weeks of disturbances in the region, where Yemeni troops have been engaged in a major offensive against the Zaidi rebels, also known as Huthis after their tribal leaders.
On Tuesday, a group of rebels entered Saudi territory and fired on border guards, killing one and wounding 11 others.
They also burned six vehicles and occupied two villages before being driven out by Saudi forces, the government said.
Pictures on the local jazannews.org website showed several Saudi village homes heavily damaged by alleged rebel mortar fire.
The Saudi statement on Friday said their attacks were necessary to prevent the rebels from being able to fire into Saudi territory.
But the rebels accused the Saudis of permitting Yemeni troops to operate against them from inside Saudi territory.
On August 11 Yemeni government forces launched a massive campaign against the rebels, driving them across the mountainous landscape toward the Saudi border.
Saudi Arabia's overt involvement has raised concerns among some experts that a "proxy war" is developing between regional rivals Riyadh and Tehran.
Yemen president Ali Abdullah Saleh -- who himself has Zaidi roots -- is heavily supported by the Saudi government. Meanwhile Sanaa accuses Iran of backing the rebels.
On October 28 Yemen said it had arrested five Iranians on a boat loaded with weapons allegedly destined for the rebels.
Late on Thursday, a US official said Washington was "concerned by the expansion of the conflict along the Saudi-Yemeni border."
"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.
"We call on all parties to the conflict to make every effort to protect civilian populations and limit damage to civilian infrastructure."
The Zaidis form the majority community in the far north of Yemen but are a minority in mainly Sunni Yemen.
The Yemen government accuses 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.
Hundreds of people have been killed or wounded in the clashes since the government launched the campaign.
Tens of thousands more have been forced to flee their homes, resulting in a humanitarian crisis complicated by a dire shortage of food and other basic necessities.