About 20 aid workers stranded at the Egypt-Gaza border for two days were allowed into the Palestinian territory Monday with badly needed medical equipment, according to a Hamas official. But others were kept out by Egyptian authorities, according to the official, Ghani Hamad, who is in charge of the Rafah border crossing guards. Egypt and Israel have enforced a strict blockade on Gaza since the militant Islamic Hamas overran the territory two years ago, allowing limited amounts of humanitarian supplies in. The 160-member group, called Hope for Gaza Convoy, was waiting to deliver 25 ambulances, a kidney dialysis machine, wheelchairs and more than $47,000 worth of medicine paid for with money raised by charities and donations, said Gerry MacLochlainn, a member of the Derry City Council in Ireland who accompanied the group. Hamad said 20 members of the group and all the equipment were allowed into Gaza. He said he did not know why Egypt kept the other aid workers out. Medical equipment has been in especially short supply since Israel's three-week offensive against militants in Gaza ended in late January. More than 1,150 Palestinians were killed and several thousand wounded during the offensive, meant to stop daily rocket barrages from Gaza at Israel.