Muslims around the world are celebrating the holiday of Eid al Fitr.

After the Ramadan month of fasting, Muslims celebrate Eid al Fitr with a day of prayers, feasts and family visits.

Capital cities including Damascus, Baghdad and Beirut were crowded with worshippers heading to mosques and cemeteries.

People attempt to catch balloons released after Eid al Fitr prayers outside El-Seddik Mosque in Cairo

Albanian Muslims celebrate Eid al Fitr prayers at Skanderbeg Square in Tirana, Albania

A Palestinian celebrates while playing with a child following Eid al Fitr prayers

Muslim women display their henna decorations at the Masjid Salaam grounds in Nairobi, Kenya

Many Muslims visit the graves of their loved ones after the early morning prayer on the first day of Eid al Fitr.

Palestinians attend Eid al-Fitr prayers at the compound that houses Al-Aqsa mosque in Jerusalem's Old City

Muslims perform their Eid al Fitr prayers at the Grand Mosque, in the holy city of Mecca, Saudi Arabia

Visitors bring bouquets of flowers, jugs of water for plants and brooms to clean gravestones.

An aerial view of Palestinians performing morning prayers to celebrate Eid al Fitr in Gaza City

Palestinians praying in the southern Gaza Strip

Outside the Mohammad al-Amin Mosque in downtown of Beirut

"After the Eid prayer we always visit our dead... to pray and pay our respects, may God have mercy and forgive them on this blessed day," said Atheer Mohamed in Baghdad's Azamiya cemetery.

Islam's holidays follow a lunar calendar.

Muslims mark the end of Ramadan and the beginning of Eid a Fitr at Platt Fields Park in Manchester

Eid al Fitr holiday celebrations by the Dome of the Rock shrine in the Al Aqsa Mosque compound in Jerusalem's Old City

Palestinian women take a selfie together following Eid al Fitr prayers in Jerusalem's Old City

Palestinian Muslims perform Eid al Fitr prayers at a soccer court, in the West Bank city of Beitunia

But some countries rely on astronomical calculations rather than physical sightings.

This frequently leads to disagreements between religious authorities in different countries - and sometimes in the same country - over the start date of Eid al Fitr.