Saudi forces have been carrying out air and artillery strikes on Yemen
Nine Saudi soldiers have been captured by Houthi rebels during fighting in northern Yemen, a rebel spokesman says.
Speaking from Germany, Yahya al-Houthi told the BBC their grievance was with the Yemeni government and urged Saudi Arabia to stay out of the conflict.
The Saudi defence ministry has confirmed nine soldiers are missing and may have been taken prisoner.
The Houthis accuse Riyadh of supporting the Yemeni armed forces by letting them launch attacks from its territory.
Later, the rebels said on their website that Saudi planes had carried out bombing raids about 30km (19 miles) inside Yemen.
A statement said the attack on Saqayn district had caused civilian casualties, but gave no further details.
Saudi forces have been carrying out air and artillery strikes on Yemen for several weeks, after the rebels killed a border guard in a raid.
The Houthis, named after the family of their leader, say they are trying to reverse the political, economic and religious marginalisation of the Zaydi Shia community.
They also accuse Saudi Arabia of supporting the Yemeni armed forces by allowing them to launch attacks from its territory, a charge both countries deny.
The Yemeni government accuses the Houthis of wanting to re-establish Zaydi clerical rule, which ended in 1962.
The Zaydi community are a minority in Yemen, but make up the majority in the north of the country.
The insurgents first took up arms against the government in 2004, after which government forces killed or captured much of the Houthi leadership.
The government launched a fresh offensive in August 2009, which has precipitated a new wave of intense fighting.
Aid agencies say tens of thousands of people have been displaced.