Four Saudi soldiers and many Yemeni rebels have been killed in intense fighting along the two countries' border, the Saudi-led coalition says.

In a statement, it said forces loyal to Yemen's former president, supported by Houthi fighters, attacked several Saudi positions on Friday.

The rebels "aimed to penetrate our borders", and were eventually repelled, the statement added.

Meanwhile, the Houthis have agreed to attend peace talks in Geneva.

The UN-brokered meeting on 14 June is aimed at ending weeks of war that has claimed more than 2,000 lives.

"We accepted the invitation of the United Nations to go to the negotiating table in Geneva without preconditions," Daifallah al-Shami, a senior member of the rebels' political wing told AFP.

GROUND ATTACK

Yemen's government, which is operating from Riyadh, also said it would attend.

A Saudi-led coalition has been bombing rebel positions in Yemen for 10 weeks, in support of the country's exiled president Abdrabbuh Mansour Hadi.

The Houthis overran the capital Sanaa last September and have gone on to seize most of the country.

Although there have been previous border skirmishes and deadly rebel fire against Saudi Arabia, Friday's battle is only the second major ground attack reported against Saudi territory.

The humanitarian crisis in Yemen has been described as "catastrophic" by the UN with 20 million civilians – 80 percent of the population - in need of aid.

At least 21 people have died during violence since Thursday in the Aden area, while there were intense coalition air raids against Daleh and Shabwa provinces.