DUBAI: Voters in Oman are casting ballots for an advisory council at a time when slumping oil prices are straining the country's finances and a civil war rages in neighboring Yemen.

The official Oman News Agency said Sunday that 590 candidates are competing for 85 seats on the Shura Council. Twenty women are among the candidates.

Sultan Qaboos bin Said granted additional powers to the council following Arab Spring-inspired protests in 2011. It can approve or offer suggested changes to draft laws, though ultimate authority rests overwhelmingly with the ruler.

The election takes place amid lingering questions about the health of 74-year-old Qaboos, who has ruled more than four decades and has no designated heir. He returned home in March after months of treatment abroad for an unspecified ailment.