WASHINGTON (AFP) The US government as a "safety precaution" revoked visas it had issued to four Palestinian recipients of prestigious Fulbright fellowships, the State Department said Tuesday.

"We had interviewed four scholars. We had issued visas," said State Department spokesman Gonzalo Gallegos.

But, Gallegos said that "subsequent to the issue of the visas to the students, who live in the Gaza Strip, we received additional information that we believe was pertinent and needed to be reviewed further before they were allowed entry into the United States," he said.

"We did what we call a prudential revocation of their visas, which is a safety precaution that we undertake to make sure that all potentially relevant facts about an alien are thoroughly explored before we admit that alien to the United States."

The spokesman did not elaborate on the source or content of the "additional information" but said the students would be allowed to resubmit their visa applications, although they would have to begin the application process from square one.

The four scholars were among a group of eight Palestinians who had hoped to travel to the United States under the sought-after Fulbright fellowship, but who were thwarted by the Israeli government which refused to approve their travel to Jerusalem for an initial interview with US authorities.

Eventually the Israeli government relented and allowed the interviews after Washington intervened on the students' behalf.

Established in 1946, the Fulbright exchange program, administered by the State Department, aims to increase mutual understanding between the citizens of the United States and other countries.

The program each year affords hundreds of academics, students and professionals around the world the opportunity to study, conduct advanced research and undertake university lecturing in the United States.

But since the Islamist Hamas movement seized control of Gaza in June 2007, Israel has sealed the territory to all but very limited humanitarian aid and severely restricted the movement of the 1.5 million Palestinians living there.

Israel is still preventing hundreds of students from leaving Gaza for educational programs in other countries, according to the Israel-based Gisha Legal Center for Freedom of Movement.