WASHINGTON - U.S. Rep. Keith Ellison and a group of high-profile U.S. Muslims have sent a letter to Hamas leader Khaled Mashaal urging the militant group to release an Israeli soldier held captive since 2006.

The letter, an effort spearheaded by the Minnesota Democrat, calls on Hamas to release Israeli soldier Gilad Shalit by invoking the Qur'an and the spirit of reconciliation at the end of Ramadan.

"Hamas' inhumane detention of Shalit undermines the Palestinian people's legitimate aspirations for human rights and a state of their own," the letter said. "We believe Hamas' harsh treatment and five-year detention of Shalit is wrong."

The letter is an attempt by top U.S. Muslims to make a direct plea to Hamas, which has said it will release Shalit only in a prisoner exchange. The soldier's imprisonment has been followed closely by Israelis since he was captured, and it remains a serious roadblock to Israeli-Palestinian peace talks.

The letter draws on a coalition of 11 Muslim leaders, including the two Muslim members of Congress, Ellison and Indiana Rep. Andre Carson, as well as former Pakistani Ambassador Akbar Ahmed and Imam Feisal Abdul Rauf, who is heading up the mosque near ground zero in New York.

"It's important that American Muslim leaders speak out on the issue of Gilad Shalit and terrorism more broadly," said Haim Malka, senior fellow at the Center for Strategic and International Studies. "But the letter is unlikely to have a direct impact on Hamas' complex decision-making process."

Hamas, which controls Gaza, has indirectly negotiated unsuccessfully with the Israelis numerous times over Shalit.

Ellison, the first Muslim elected to Congress, told the Star Tribune he hopes the letter will help change someone's mind, though he isn't optimistic. Ellison met with Shalit's family in 2007, he said, and was prompted to act in part by the recent anniversary of the capture.

"It just seemed like a humane, decent thing to do," Ellison said of sending the letter. "I don't think [Shalit's captivity is] helping the Palestinian people get a state, which I earnestly pray that they get. I think it hardens Israeli hearts and makes it more difficult to move the ball."

Ellison has tried to strike a balance between his support for Israel and the Palestinians. He says that while he supports rights for Palestinians, he denounces Hamas as a terrorist organization and refuses to speak with them on any issue beyond releasing Shalit.

Ahmed, who is currently a professor at American University, said the letter's writers hoped to appeal to Hamas by invoking Islam's "strong call of compassion and mercy."

"A letter like this is a shot in the dark," Ahmed said, "and we can only hope it lands in the right place and touches someone's heart."

Jeremy Herb • 202-408-2723 Twitter: @StribHerb