WASHINGTON -- The Pentagon sprayed biological and chemical agents off the coast of San Diego during the Cold War, part of a series of previously undisclosed tests in several states that exposed troops and perhaps thousands of civilians to the compounds, defense officials said Wednesday.

In all, 27 newly disclosed secret tests were conducted in California, Alaska, Florida, Hawaii, Maryland and Utah, officials said. The tests, conducted from 1962 to 1973, were also carried out in Canada and the United Kingdom.

In February 1966, a Navy vessel in the Pacific Ocean off the coast of San Diego was sprayed with methylacetoacetate, or MA, a chemical that irritates the eyes, skin and respiratory tract but is not considered hazardous by the Environmental Protection Agency.

In a second test in the summer of 1968, MA and Bacillus globigii, or BG, were released in the same waters. A bacterium related to anthrax, BG was later found to infect people with weak immune systems. No civilians are thought to have been exposed to harmful agents in those tests because they were carried out over the ocean.

It was the first time the Pentagon has acknowledged that it used the agents on U.S. soil and that civilians may have been exposed during the tests. The Defense Department previously revealed that 10 tests were carried out during the Cold War on U.S. ships to determine how they would perform under chemical or biological attack.

The Defense Department released the information at a House Veterans Affairs Committee meeting Wednesday; some elements were leaked to reporters Tuesday.

Military officials insisted that none of the agents used near civilians was thought at the time to be dangerous, although some—including E. coli bacteria—were later found to be harmful, even deadly.

In 21 tests on land and six newly reported tests at sea overseen by the Deseret Test Center at Ft. Douglas, Utah, live biological agents and lethal chemicals—including sarin and VX—were sprayed not only in the six states, but at or near military facilities in Puerto Rico, Canada, the United Kingdom, the Marshall Islands, Baker Island and over international waters in the Pacific Ocean.

The 37 tests disclosed so far affected about 5,000 service members at sea and 500 on land from 1962 to 1973, defense officials said. The Pentagon has notified about 1,400 of those soldiers about the secret testing regimen, dubbed "Project 112."

The Deseret test center reported that four people were infected at the time and successfully treated. Veterans Affairs officials said they were studying the phenomenon; 53 veterans have filed health claims since the 1990s. The claims blame what they say was their exposure to the chemical or biological agents for a variety of ailments, including muscular, skeletal, digestive, hearing, skin and cardiovascular disorders.

Defense officials said the Pentagon has no process for notifying civilians who may have been exposed in the U.S., including those possibly numbering "into the thousands" on Oahu, Hawaii.

Pentagon officials believe local authorities were notified of the tests at the time, said William Winkenwerder Jr., assistant Defense secretary for health affairs, but most citizens apparently were not. Veterans advocates said lower-level soldiers also were unaware, although defense officials insisted the soldiers were protected by chemical gear and masks.

"We're making this information available so that anyone who believes there may have been some ill effect could come forward," Winkenwerder said.

Civilians were not believed to have been affected in California because the four tests conducted there—including two first reported Wednesday—were all conducted off the San Diego coast in the Pacific Ocean, according to the Pentagon analysis.

Defense officials insisted that civilians were exposed only to live biological agents that simulated more deadly agents in the way they spread, but were themselves believed to be harmless. However, the simulated substances included E. coli and other agents that were later found to be harmful or fatal to young children, the elderly and those with compromised immune systems.

Even soldiers and sailors exposed during the tests "may not have known all the details of these tests," Winkenwerder said.

"Most of these people didn't have a clue what they were part of," said Kirt Love, a veterans advocate with the Desert Storm Battle Registry who contended that in many cases only senior officers were aware of the tests. "These were not safe agents at the time."

After the report was released of the House Veterans Affairs Committee hearing, it was detailed at a Pentagon briefing. Defense officials said the tests were conducted for potential offensive use against U.S. enemies and for defense against the Cold War biological and chemical weapons arsenal amassed by the Soviet Union.

The Navy trials tested the ability of ships and sailors, clad in chemical defense gear, to perform under a chemical or biological attack at sea. The land-based tests were done to evaluate how the agents dispersed, officials said. Desert tests such as those in Utah helped the Pentagon amass much of the information the military has on how chemical and biological agents would perform in desert areas such as Iraq, said Anna Johnson-Winegar, the Pentagon's assistant secretary for chemical and biological defense.

"The purpose of these operational tests was to test equipment, procedures, military tactics, etc., and to learn more about biological and chemical agents," Winkenwerder said. "The tests were not conducted to evaluate the effects of dangerous agents on people."

The United States ended its biological weapons program in the 1960s and in 1997 signed a treaty agreeing to destroy all of its chemical weapons. Funding and disposal issues have delayed much of that process, leaving stores of lethal chemicals at several military sites throughout the nation.

Today, defense officials insist that the only testing of toxic and biological agents in the United States is given to chemical specialists among the armed services at a tightly contained testing facility at Ft. Leonard Wood, Mo. So-called stimulants still are used elsewhere.

The disclosures are unlikely to be the last from Project 112. The military had planned 134 tests; 46 were conducted, 62 were canceled and the status of the remainder is unclear. The newly disclosed tests used a variety of agents under various conditions.

Tests in the late 1960s in Porton Down, England, and Ralson, Canada, used tabun and soman, two deadly nerve agents.

In the 1965 Oahu test, BG was sprayed in a simulated attack called "Big Tom." Near Ft. Greely, Alaska, researchers tested how deadly sarin gas, the toxin members of the Aum Supreme Truth cult used in 1995 to kill commuters in the Tokyo subway, would disperse after being released from artillery shells and rockets in dense forests in a test dubbed "Devil Hole I" in 1965. A year later, VX agent, which lingers like motor oil in deadly pools, was released by artillery shells in "Devil Hole II."