SEOUL, South Korea (AP) - North Korea fired seven ballistic missiles off its eastern coast Saturday, South Korea said, a violation of U.N. resolutions and an apparent message of defiance to the United States on its Independence Day.

The launches, which came two days after North Korea fired what were believed to be four short-range cruise missiles, will likely further escalate tensions in the region as the U.S. tries to muster support for tough enforcement of the latest U.N. Security Council resolution imposed on the communist regime for its May nuclear test.

South Korea's Joint Chiefs of Staff said three missiles were fired early Saturday, a fourth around noon and three more in the afternoon. The Defense Ministry said that the missiles were ballistic and are believed to have flown more than 250 miles (400 kilometers).

"Our military is fully ready to counter any North Korean threats and provocations based on strong South Korea-U.S. combined defense posture," the Joint Chiefs of Staff said in a statement.

South Korea's Yonhap news agency said the first three appeared to be Rodong missiles while the rest were an upgraded version of Scud-C missiles, citing intelligence authorities.

The Defense Ministry said it could not confirm the report, saying more analysis needs to be done.

Scud-C missiles have a range of up to 300 miles (500 kilometers), which could hit most of South Korea. The Rodong has a range of up to 800 miles (1,300 kilometers), putting most parts of Japan within striking distance. Yonhap said, however, that the range of the Rodong missiles launched Saturday had been reduced.

U.N. resolutions ban North Korea from firing Scuds, medium-range missiles or long-range missiles. Among the U.N. measures is Resolution 1874, passed after North Korea's May 25 nuclear test, that prohibits any launch using ballistic missile technology.

Thursday's missile launches, on the other hand, did not violate the resolution, according to South Korea's Foreign Ministry. Kim Tae-woo, vice president of the Korea Institute for Defense Analyses, said they were believed to be cruise missiles.

Ballistic missiles are guided during their ascent out of the atmosphere but fall freely when they descend. Cruise missiles fly low and straight to their target.

The North has a record of timing its missile tests for U.S. Independence Day, which fell on Saturday.

"The missiles were seen as part of military exercises, but North Korea also appeared to have sent a message to the U.S. through the missile launches," a senior official in South Korea's presidential office said, without elaborating.

The official told The Associated Press that North Korea could fire more missiles in coming days, but said there was little possibility it could fire an intercontinental ballistic missile, as it threatened in April.

He spoke on condition of anonymity because he was not authorized to speak to media.

Yonhap said North Korea was pulling out personnel from its missile launch site and was allowing ships to sail again in waters off its east coast - an indication no more missiles would be launched in the near future. Yonhap cited an unidentified military official.

The Defense Ministry said it could not confirm the report.

The North had initially warned ships to stay away from its east coast through July 10 for military exercises.

But the South Korea-U.S. combined forces command will not change its heightened alert level until tensions are eased, the Defense Ministry said. The command increased surveillance in May, when the North threatened military strikes on South Korean and U.S. troops.

The U.S. has 28,500 troops in South Korea as a deterrent against North Korea.

Daniel Pinkston, a Seoul-based analyst for the International Crisis Group think tank, said both political and military reasons were behind the launches.

"I think it's a demonstration of their defiance and rejection of the U.N. Security Council Resolution 1874, for one thing, and to demonstrate their military power capabilities to any potential adversaries," Pinkston said.

He also pointed out that July 4 is not only U.S. Independence Day but also the anniversary of a 1972 joint communique in which the two Koreas agreed to work toward peacefully reunifying their divided peninsula.

During the U.S. Independence Day holiday in 2006, Pyongyang fired a barrage of missiles, including a long-range Taepodong-2 that broke apart and fell into the ocean less than a minute after liftoff. Those launches, which occurred on July 5 in North Korea, also came amid tensions with the U.S. over North Korea's nuclear program.

North Korea's state news agency carried no reports on the launches.

South Korea and Japan, which are within easy range of North Korean missiles, condemned the launches as a "provocative" act that violates the U.N. resolution.

South Korea "expressed deep regret over the North's continuous behavior that escalates tensions in Northeast Asia by repeatedly defying" the resolution, the Foreign Ministry said in a statement.

In Tokyo, Chief Cabinet Secretary Takeo Kawamura said in a statement that the launch of missiles "is a serious act of provocation against the security of neighboring countries, including Japan, and is against the resolution of the U.N Security Council."

In Beijing, a Foreign Ministry spokesman said he had no immediate comment. China is the North's closest ally.

Associated Press writers Yuri Kageyama and Tomoko A. Hosaka in Tokyo, Henry Sanderson in Beijing, and Jae-soon Chang in Seoul contributed to this report.