Following a closure due to a shark activity in the area, ocean waters in the San Clemente area were reopened Tuesday, but a shark advisory remained in effect warning swimmers to enter the surf at their own risk.

The shark advisory will remain in place until at least 8 p.m. Tuesday, “pending no additional shark sightings,” according to city officials.

A shark knocked a surfer off of his board off the coast of San Clemente late Monday morning, prompting authorities to close the water to swimmers and others on the busy Memorial Day holiday. City officials said at the time the closure was due to “confirmed aggressive shark behavior” in the water in the vicinity of T-Street Beach.

The beaches remained open, but water access was closed.

City Councilman Chris Duncan told CBS2 that surfers reported the activity to lifeguards, who reviewed surveillance footage and found video of the surfer being knocked off his board.

According to CBS2, officials from the Long Beach State University shark lab were consulted, and they determined the culprit was likely a juvenile great white shark.

No injuries were reported.

City News Service contributed to this article.

A shark advisory was issued Saturday after a surfer spotted one at Silver Strand State Beach, Coronado lifeguards confirmed .

The surfer said the shark appeared to be a great white about 10 feet long, according to a Facebook post.

He claims to have worked on fishing boats for many years and has had several encounters with great white sharks previously, stated the post.

“He knows what he saw,” added the post.

Coronado lifeguards explained that the advisory does not apply to the beaches in Coronado. There is only an advisory in effect at Silver Strand State Beach in San Diego, just south of Coronado’s beaches.

No further information was immediately available.