According to journalists from the AFP news agency, loud explosions were heard in Riyadh on Monday evening.
The attacks come after Yemen's Saudi-backed government forces regained control of the strategically important Bab al-Mandab Strait. More than 1,000 raids have been carried out against Houthi targets, according to the Yemeni military.
Saudi Arabia's Foreign Ministry condemned the Houthis' attacks on civilian and economic targets in the country. In a statement, the ministry reiterated accusations that the Houthi movement had attempted to attack the holy cities of Mecca and Medina - something the movement denies.
Turkey and Pakistan have announced that they will immediately send forces to Saudi Arabia, according to the three countries' defence alliance.
