The main United Nations agency in Gaza has cancelled the annual marathon in the small Palestinian territory after ruling Hamas Islamists banned women from the race.
Hamas said having women in the annual event, scheduled for April 10, contravened Islamic tradition even though dozens of Palestinian schoolgirls had started the two previous marathons.
"This disappointing decision follows discussions with the authorities in Gaza, who have insisted that no women should participate," the United Nations Relief and Works Agency (UNRWA), which sponsors the race, said in a statement.
This year's field of 1,500 schoolchildren and 800 adults was to have included a record number of women - 260 Palestinians and 119 foreigners, UNRWA said. The children's participation is symbolic - they begin the race but run only a few hundred metres, while the adults do the full 42 km (26 miles).
"The marathon was an annual event to show solidarity with the Palestinian people and to raise funds for summer camps organised by UNRWA which serve at least 250,000 schoolchildren," said Adnan Abu Hasna, the agency's media adviser in Gaza.
Relations between UNRWA and Hamas, which has controlled the Gaza Strip since 2007 and is shunned by the West over its hostility towards Israel, have been strained at times.
Some Hamas officials have accused UNRWA of failing to include representatives of the Gaza government when UNRWA has hosted meetings with international visitors. Several Hamas lawmakers have been critical of the curriculum in UNRWA-run schools.
Founded in 1949, UNRWA provides food and other emergency assistance to more than two-thirds of the 1.6 million population in the cramped, coastal territory.
Human rights groups have accused Hamas of pressuring women to cover their heads in public and using police to harass young couples in the streets and on beaches. Hamas has denied it is trying to enforce any modesty code.