A Houthi ballistic missile attack on the Yemeni province of Marib has killed and injured 29 civilians, including women and children, according to the country's information minister. In a tweet on Monday, Muammar al-Iryani said two ballistic missiles used in the attack hit a mosque and a religious school. The Marib governor's office said the attack took place late on Sunday. An explosion near the entrance to the international airport of Yemen's southern port city of Aden on Saturday resulted in at least six deaths and around 20 injured, a senior security source and a medical source told Reuters, but it was not clear whether the incident was an attack. An airport official said a small truck blew up at an outer gate to the airport, while a local official and two security sources said the vehicle was carrying petroleum products. The blast was strong and was heard across the city. Nearby residents' windows were smashed. Fighting between government forces and Houthis has escalated in recent months. The United Nations says some 10,000 people were displaced in September by fighting in Marib, the internationally-recognised government's last northern stronghold. It is calling for a humanitarian corridor for aid. The war in Yemen and ensuing economic collapse, as well as restrictions on imports to Houthi-held areas, have caused what the UN says is the world's biggest humanitarian crisis, with 16 million people facing starvation. — Agencies