Millions of Muslims across the globe — including in countries like India, Indonesia, Turkey, Russia and Pakistan — are celebrating Eid al-Adha, Islam’s most revered observance.

Known as the Feast of Sacrifice or “big Eid,” it is one of the two major religious festivals of Islam. The other, Eid al-Fitr, occurs at the end of Ramadan, the holy month of fasting.

In Pakistan, the faithful crowded into mosques and prayer grounds on Saturday to offer prayers and sacrifice goats and cows.

Security was tight, as religious extremists have carried out bombings across the country in recent years.