The Muslim festival Eid al-Adha - which means "feast of the sacrifice" - began on Sunday evening and is marked by special prayers and feasts.
Each year Muslims gather for the occasion that commemorates the Prophet Ibrahim's willingness to sacrifice his son on the command of God. Ibrahim was eventually given a lamb to sacrifice instead.
Eid al-Adha usually begins on the last day of the Hajj, the annual Muslim pilgrimage to Mecca in Saudi Arabia.
It is the second Islamic festival of the year, and follows Eid al-Fitr which marks the end of Ramadan, the holy month of fasting.
Here is a selection of pictures of celebrations from around the world on Monday.