SANTOS, Brazil (AP) ? Thousands of trucks rumble into South America's largest port each day, hauling everything from auto parts to coffee bound for Europe, Asia and the United States. At least that's what the paperwork says, although it turned out to be wrong in one telling security breach involving about 40 containers of Brazilian coffee beans last year.

Without opening the containers, it would take an X-ray or radiation detectors to reveal what's truly inside. Those are two of several screening measures scheduled to start on July 1 to prevent terrorists from shipping explosives, guns and other deadly material, although only one in ten ports around the world has met the requirements so far.

Santos port officials say their security plan will be approved before July 1. But it will take months to implement, including constructing miles of higher fences, installing an electronic identification system for 20,000 people who pass through the port's 60 entrances daily and putting up a closed circuit monitoring system with nearly 500 cameras. Now, small ferries motor near enormous freighters taking on stacks of containers as security guards give paperwork cursory checks. Getting inside the port and close to docked ships isn't hard, a factor that experts say could make it an inviting place for terrorists planning to hijack ships or use containers to smuggle weapons of mass destruction to overseas targets.

Failure to comply with the July 1 date imposed by the International Maritime Organisation, a UN agency, could cause trade problems if countries like the United States turn away or perform lengthy inspections on ships calling at ports that don't meet the new security standards. Ships heading to the United States from ports that don't comply with the code, for example, could be searched by the US Coast Guard and, in the most extreme cases, be ordered back to sea.

By mid-June, only 654 of the 6,114 ports subject to the international security code ? established after pressure by the United States in the wake of the September 11 attacks ? were in compliance.

Chris Austen, chief executive of the British firm Maritime & Underwater Security Consultants, is working with 300 ports and many are still ordering equipment such as closed-circuit TVs and training.