GAZA CITY, Gaza Strip - The supreme leader of Hamas threatened violence if an international aid embargo isn't lifted and demanded in an interview published Monday that Israel release top Palestinian leaders in return for a captured soldier.

A Palestinian unity government replaced a Hamas-led one that was formed after the Islamist group won a national election in 2006. The international community cut off aid to the Palestinians after that government refused demands to recognize Israel, renounce violence and accept previous signed peace agreements.

Though the government now includes the more moderate Fatah, it has not explicitly accepted any of those conditions, and most Western nations are maintaining the aid boycott to the government, while funding some aid projects directly.

"We are doing the impossible to end the embargo on our people ... If, God forbid, it continues ... the results will be serious," Khaled Mashaal told the Palestinian newspaper Al-Ayam. "The explosion will be in the face of the Zionist enemy."

Mashaal said that Hamas intended to demand prominent Palestinian leaders, including Marwan Barghouti, a popular leader of the rival Fatah, in exchange for the captured soldier.

Israel has said it will not release Barghouti, who is serving five consecutive life terms for his role in shooting attacks that killed four Israelis and a Greek monk.

In the interview, Mashaal accused Israeli Prime Minister Ehud Olmert of delaying the exchange deal in "the last quarter hour."

A list of Palestinian prisoners the group wants freed in the first stage was handed over to Israel by Egyptian mediators, but the group has not received a response, Mashaal said. Olmert has said in public that the list is not acceptable.

Though the soldier's captors are not known to have offered evidence that he is alive and have prevented Red Cross representatives from meeting him, Mashaal told the newspaper that the captive soldier was being treated humanely.