"The situation is calm on all fronts in Saada province," the centre of the sic-year old rebellion, said one military source.
"But the calm is precarious," said another.
A spokesman for rebel leader Abdul Malak al-Huthi confirmed that, adding that the "ceasefire is being respected and the situation is developing positively".
A ceasefire in the government's latest, six-month campaign to crush the rebellion went into effect at midnight (2100 GMT) on Thursday.
However, only hours later Yemen's army accused the rebels of breaking the truce, saying they had killed four soldiers in a string of attacks.
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