Palestinians and their supporters are running the West Bank's first marathon.
Itidal Abdul-Ghani of the Palestinian Olympic Committee says some 1,000 people are participating in Sunday's race, which includes shorter 10-kilometer and 20-kilometer options.
The marathon, taking place in cool, rainy weather, loops four times around Bethlehem, the traditional birthplace of Jesus.
Abdul-Ghani says that because of Israel's separation barrier surrounding parts of the city, and its control over nearby land, there's not enough space to do a straight 42-kilometer (26 mile) run.
Israel says the barrier is needed to keep out attackers. Palestinians say it's a land grab.
The marathon comes six days after the Boston Marathon bombings and coincides with the London Marathon.
Some runners wore T-shirts honoring the Boston Marathon victims.