The leader of Yemen's Shia Houthi rebels, who control Sanaa and are battling al-Qaeda-linked fighters, has dismissed the threat of UN Security Council sanctions.

Delivering a speech in the capital on Tuesday in honour of Ashoura, Abdel-Malek al-Houthi told supporters: "We are not afraid," and criticised the country's embattled leadership for failing to take the lead in combatting al-Qaeda.

The council last month expressed deep concern over the crisis in the country, urging the new government to facilitate reforms, especially in the army and security forces, and saying it was prepared to impose sanctions on "spoilers" threatening the country's peace, security and stability.

Al-Houthi's address came as at least 30 people were killed in clashes earlier on Tuesday between his forces and al-Qaeda fighters in the central town of Radda.

The Shia rebel leader warned that his forces were raising their "combat readiness" and accused President Abed Rabbo Mansour Hadi of failing to combat al-Qaeda's powerful Yemeni affiliate and other Sunni fighters.

The Houthis swept down from their northern strongholds and overran Sanaa in September.

The speech appeared to signal an escalation against the country's leadership and may feed fears among Yemenis that the rebels are looking to expand their already considerable territorial gains.

Houthi and al-Qaeda fighters exchanged heavy artillery fire in Radda in fighting that lasted until early Tuesday.

The violence in Radda has left several civilians dead, with houses and cars damaged and shelling forcing dozens of families to flee the town, according to security officials.

Source: Agencies