Green Party presidential candidate Cynthia McKinney, unimpeded by the "closed military zone" imposed by Israel, was among 16 people aboard a medical supply boat that collided with an Israeli naval ship Tuesday as it tried to enter coastal waters around Gaza.

The yacht, owned by the U.S.-based Free Gaza Movement, was reportedly carrying 3.5 tons of medical supplies donated by Cyprus. A press release from the group claimed "several Israeli gunboats intercepted the Dignity she was heading on a mission of mercy to Gaza." They said the Israeli military fired machine guns into the water in an attempt to stop the Dignity's progress.

The boat, registered under the flag of Gibraltar and with an English captain, reportedly took on water and experienced engine problems, according to the group's Web site. It also said the incident occurred 90 miles offshore in international water. The boat's captain was given permission to dock in Lebanon, where it was regrouping to try again.

Israel's foreign ministry spokesman Yigal Palmor told Reuters that an Israeli vessel and the 60-foot Free Gaza Movement boat did make "physical contact," but only after the aid boat failed to respond to radio contact. He denied any gunfire had occurred, and he said no one was hurt in the incident. He told Reuters the Israeli ship escorted the damaged boat back to Cypriot territorial waters.