An American activist who came to Israel to take part in a pro-Palestinian march has been held in a detention facility for more than a week after being refused entry to the country, her lawyer said Thursday.

Ann Petter, 44, a New York City graphic designer, arrived at Israel's international airport in Tel Aviv on June 23, said her lawyer, Yael Berda.

Petter refused a police request to return to the United States and has been held at the airport pending a court hearing on her petition to have the order rescinded, the lawyer said.

A spokeswoman for the Interior Ministry said police had determined that Petter was a threat to Israel's security and had denied her entry.

Petter is affiliated with the International Solidarity Movement (search), Berda said. ISM is a pro-Palestinian group whose members often place themselves between Israeli forces and Palestinians to try to stop the Israeli military from carrying out operations.

Berda said Petter planned on taking part in a July march to protest Israel's West Bank separation barrier (search), which Palestinians say is an Israeli effort to annex land in the West Bank.

Israel says the barrier is necessary to stop Palestinian militants from carrying out attacks inside the country.

Petter participated in an anti-Israel demonstration in the West Bank last July, but was not arrested, Berda said.

In March 2003, ISM activist Rachel Corrie (search), 23, of Olympia, Wash., was crushed to death by an Israeli army bulldozer in a Palestinian refugee camp in the Gaza Strip (search) while trying to stop soldiers from carrying out a house demolition.

An Israeli army investigation concluded Corrie's death was accidental.