Tens of thousands of Yemenis have been displaced by fighting

A number of displaced Yemenis have been killed during a fight between the army and rebels at a camps run by the UN refugee agency, the agency has said.

The UNHCR described women and children being among the dead and injured at al-Sam camp in Saada province, but was not able to supply the exact numbers.

It said the deaths occurred when a rocket or a mortar shell hit the camp.

Saada has seen some of the worst fighting between the government and Houthi rebels from the Zaidi Shia sect.

The UN said around 500 people were staying at the facility and that the security situation in that area had been "deteriorating over the past few days" with "indiscriminate targeting of Yemeni civilians forced to flee their homes".

Houthi rebels first took up arms against the government in 2004.

They say they want greater autonomy and an public role for their version of Shia Islam, complaining of discrimination by the government in Sanaa.

Yemeni officials accuse Houthis, who are the majority in the north of Yemen, of wanting to re-establish Shia clerical rule.

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.