The ceasefire has largely held but signs of instability still worry Saudi Arabia, which borders Yemen and which was briefly drawn into the war last year when fighters seized Saudi border areas.

Fighters attacked on Friday the home of a pro-government tribal leader, killing three people.

Under pressure

The Houthis accuse the government of religious and socio-economic discrimination.

More than 250,000 people have been displaced by the war between the government and the Houthis.

In depth

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Yemen has faced international pressure to quell its domestic conflicts, including an increasingly violent secessionist movement in the south, and to combat a resurgent al-Qaeda affiliate in the country.

Under the truce terms, the Houthis should free all prisoners, open roads in the north, withdraw from government buildings, return weapons seized from security forces, and hand over captured army posts.

They also had to pledge not to attack Saudi Arabia.

The Houthis have engaged in sporadic clashes with government forces since 2004.

However, the situation turned particularly violent after Yemeni government forces launched a military offensive Operation Scorched Earth, against the group in August 2009.

Saudi Arabia joined the fray in November after accusing the Houthis of killing a border guard and occupying two villages inside Saudi territory.

Western governments and Saudi Arabia, the world's biggest oil exporter, fear al-Qaeda is exploiting instability on many fronts in Yemen to recruit and train fighters for attacks in the region and beyond.