Israeli army roadblocks have prevented ambulances from moving injured and sick Palestinians in about 600 cases during the past two years of Mideast violence, a group of Israeli doctors said Tuesday.

In a report that provided details of dozens of incidents, the Physicians for Human Rights said the network of Israeli roadblocks has often blocked or delayed Palestinians from receiving prompt medical care, including pregnant women and people who had suffered heart attacks.

"As an Israeli and a doctor, I am ashamed," said Dr. Ilan Gal, a member of the group. He said 39 Palestinian women have given birth at army checkpoints over the past two years.

Israel's military has sealed off the Palestinian cities in the West Bank in an effort to prevent Palestinian suicide bomb attacks. The army has said repeatedly that it allows humanitarian cases to pass checkpoints, but the report by the group cited cases of patients dying after ambulances or cars carrying sick people were delayed for hours.

"Movement of Palestinians is sometimes limited if there are grounds to suppose that suicide bombers will leave a certain area in order to carry out terrorist activities," Capt. Enrietta Levy wrote in the military's response to the report.

Even when restrictions are in place, "unequivocal instructions are given to enable movement ... in humanitarian cases," Levy wrote.

In the report entitled "Organized Injustice - the Right to Health in the Occupied Territories under Closure and Siege," the doctors also accused the army of preventing vital medical supplies, such as oxygen, from reaching hospitals.

The army has prevented ambulances from moving injured and sick people in about 600 cases, said Gal, noting that the number of Palestinian babies born at home has gone up sharply. The group's figures came from a variety of sources, but were not tabulated by the organization itself.

The army says it must stop and check ambulances because Palestinians have used them to smuggle weapons and militants.

After Israel captured the West Bank and the Gaza Strip in the 1967 Mideast war, it built hospitals for the Palestinians and opened its own hospitals to Palestinian patients, said Dr. Eran Dolev, a former Israeli army Surgeon General, who is now director of internal medicine at Ichilov Hospital in Tel Aviv.

However, the number of Palestinians arriving at Ichilov has dropped drastically over the past two years, and those who do get there are in much worse condition, said Dolev, chairman of the ethics committee of the Israel Medical Association.

"When you take control of an area you have to accept responsibility for the people living there," he said. "In the past two years we have gone back to the Palestinian areas but we have not taken responsibility for the health of the people."