TEL AVIV, Israel (Reuters) - Israel has arrested 13 U.N. employees and plans to indict them for "suspected links to terrorism," an Israeli army officer said Tuesday. Maj.-Gen. Yisrael Ziv, speaking to reporters, did not say when they were arrested. His comments came after Israel backed away from an accusation that Palestinian militants had used a U.N. ambulance in Gaza to transport a rocket to be fired at Israel. "We have in our hands a list of 13 detainees who are to be indicted, they are U.N. people with suspected links to terrorism," Ziv said.