SANAA: Shiite rebels on Tuesday accused Yemen's army of cooperating with Saudi forces to launch attacks against them, and also said they had defeated a multi-pronged Saudi assault from across the border.

"The people's army charged with protecting the border is cooperating with the Saudi army in bombing and ground attacks... against the country and its sons," a statement from the Zaidi rebels, also known as Huthis, said.

The Huthis have previously accused both mainly Sunni countries of cooperating against them, and allege that Saudi Arabia allows Yemeni forces to attack rebel positions from inside Saudi territory.

In a separate statement, the Huthis said they had defeated a three-pronged Saudi attack into Yemen.

"The Saudi attack continued on three fronts, but two were broken by Monday evening," it said.

"The attack on the third front continued until night, but was broken completely and the (Saudi) aggressors suffered heavy losses in men and materiel."

Witnesses in the frontier area told AFP that clashes between the Saudis and rebels continued on Tuesday, and that there were intense artillery strikes and air raids on Huthi positions all along the border.

It was not clear if the bombardment and air raids were launched by Saudi or Yemeni forces.

The rebels said that after they had defeated the Saudi advance, bombing resumed along the border, and continued until early on Tuesday.

The bombing targeted the Jebel al-Dukhan, Jebel Rumayh, Jebel al-Madoud, Malaheez, Shedah and Hasama areas and various border villages, they said.

Saudi forces entered the fray on November 4 after rebels killed a border guard and occupied two small villages inside Saudi territory in protest at alleged Riyadh backing for Sanaa.

The Huthi rebels have clashed with Yemeni forces on and off in their rugged mountain stronghold of Saada province and surrounding areas since 2004.

Sanaa launched "Operation Scorched Earth" on August 11, in an all-out assault on the rebels who claim of being marginalised and oppressed by the government.