A stowaway with more than 500 pounds of cocaine and a gun was found on board a barge off the coast of Puerto Rico, the U.S. Coast Guard said Thursday, marking the second time this year that authorities detained a stowaway holding a huge stash of drugs in the same harbor.

Crewmembers from two Coast Guard Cutters joined forces with a Homeland Security task force to apprehend the stowaway after boarding the Crimson Clover barge in the San Juan Harbor on Tuesday, officials said in a news release. During the operation, officers located a stowaway who was in possession of a firearm and nine bales of cocaine weighing approximately 237.75 kilograms, or about 524 pounds.

The U.S. Coast Guard Cutter Isaac Mayo later met with law enforcement partners at Coast Guard Base San Juan, and took custody of the alleged drug smuggler, the weapon and the cocaine, which was estimated to have a street value of $4.8 million. Authorities have not identified the suspect.

The Coast Guard released images of the barge, the alleged drugs and officers hauling the bales onto the shore.

"A collective pool of experience and available assets led to a safe boarding and a discovery of cocaine aboard the barge, which further deters smuggling organizations from exploiting incoming commercial vessels to conduct human and drug trafficking activities within our area of responsibility," Lt. Cmdr. Ross Markham said in a statement.

The arrest and seizure comes amid ramped up efforts by the U.S. to target  drug trafficking and human smuggling in the Caribbean Sea and eastern Pacific Ocean. In addition to routine Coast Guard interceptions of narcotics on the open seas, the Trump administration has continued a monthslong campaign of military strikes on alleged drug-running boats, killing more than 200 people.

In February, a stowaway was arrested after he was allegedly found floating in a Puerto Rican harbor with 789 pounds of cocaine.   The Coast Guard recovered the suspect from the water, as well as 10 bales of contraband wrapped in brown bags.

The month after that, authorities seized cocaine worth an estimated $12 million from a boat off the island's north coast.