Dry Tortugas National Park in the Florida Keys is temporarily closed to the public due to an influx of migrants from Cuba.

The closure, which went into effect on Monday, is expected to last several days “while law enforcement and medical personnel evaluate, provide care for and coordinate transport to Key West for approximately 300 migrants who arrived in the park over the past couple of days,” according to a National Park Service press release.

The park is about 70 miles (113 kilometers) west of Key West and is only accessibly by boat or seaplane. Dry Tortugas covers about 100 square miles of mostly water and includes seven small islands. It is within the Florida Keys National Marine Sanctuary.

“Like elsewhere in the Florida Keys, the park has recently seen an increase in people arriving by boat from Cuba and landing on the islands of Dry Tortugas National Park,” NPS said Monday.