The United States objected to the release of some of the 477 Palestinian prisoners released today in exchange for a captured Israeli soldier because they were involved in attacks on Americans, the State Department said today.

“We have looked at some of these individuals and we’ve communicated our position after we became aware that specific individuals have been identified as part of this release,” State Department deputy spokesman Mark Toner said. He said, however, that the State Department welcomed the release of Gilad Shalit, who had been held in Gaza for more than five years by the militant group Hamas.

“As a matter of principal, the U.S. opposes the release of individuals who have been convicted of crimes against Americans,” he added.

Toner declined to identify the individual prisoners of concern. He said he was unaware whether Israel had chosen not to release any of the individuals due to American concerns.

A State Department official, speaking anonymously in order to discuss the sensitive issue, confirmed that multiple individuals were released despite the American objections.

The Shalit case was big news in Israel. His family camped out in front of the prime minister’s office for years to keep the pressure on the Israeli government to secure his release. When the prisoner swap, which will ultimately send about 1,000 jailed Palestinians back home, was announced last week it was also met with concerns that Israel was giving up too much for Shalit’s freedom and that it could set a precedent for future hostage situations.

The Israeli cabinet voted to approve the swap last week and today Shalit was greeted in his hometown by cheering crowds waving Israeli flags.

Israel is reportedly considering another prisoner swap, this time with Egypt in exchange for an Israeli-American student who was arrested there and accused of spying for Israel.