ALBANY (CBS / AP) — Police have sealed off a patch of University of California, Berkeley land that has been occupied by protesters for nearly three weeks.

University police went to the property in Albany around noon Thursday and announced it was closed to pedestrian traffic.

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Officers were allowing people to leave, but no one has been allowed to enter the 10-acre site.

KCBS’ Chris Filippi Reports:

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The move by police comes after officers on Wednesday put barricades around the property to keep vehicles from coming and going.

The university also filed a lawsuit against the protesters on Wednesday, saying they had established an illegal encampment.

The protesters, on the property since April 22, have pitched tents and planted crops to protest planned housing and commercial development nearby.

University officials claim the protesters are disrupting agricultural research by faculty scientists and students.

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