Seven people died Sunday after a vehicle exploded near a hospital in Yemen's northeastern province of Mareb.
The explosion took place near a hospital controlled by the Houthi, a Zaidi Shia insurgent group that signed a peace deal with the Yemeni government last week.
Sources told CNN at least 24 Houthi were injured in the attack, three of whom were in critical condition.
The Yemeni government hasn't identified the group to blame for the attack, but a Twitter account linked to al-Qaida in the Arabian Peninsula claimed responsibility.
Mareb is a Sunni tribal stronghold and experts told CNN the attack against the Houthi was no surprise.
"After the Houthi victory in Sanaa, al-Qaida knows that Houthis will plan to expand to new areas, mainly Mareb and Baitha provinces. The more they infiltrate Mareb, the more car bombs will target their fighters," said Abdul Salam Mohammed, president of the Sanaa-based Abaad Strategic Center.