Washington, USA - Bowing and mouthing prayers, Saleh Williams prostrates himself on a white sheet beside his colleagues. For these Muslims, Friday worship takes place not in a mosque, but a meeting room in the Capitol -- at the heart of US democracy.
This gathering, for the Friday worship known as jummah, is the only Muslim event in the Capitol. But it is just one of many prayer and religious study groups of various faiths held by Congress members, their staffers and other employees, inside the federal buildings where the nation's laws are made.
Senate Chaplain Barry Black holds separate "prayer breakfasts" and Bible study groups in the upper house for senators, their spouses, and for less senior staffers or employees.
"You can get, on a very good week, 50 percent of the senators participating in the prayer breakfasts or the Bible study," Black said. "And they do so obviously on a bipartisan basis."
There are also Torah studies involving Jewish staffers, he said. "But a number of Christian people attend those studies as well."
Ever since the making of the US Constitution in 1787 when Benjamin Franklin asked that each day's business start with a prayer, religion has been central to political life and the lives of many who work here.
The jummah is the most recent sign that faith-based groups are thriving in the corridors of power.
"Actually praying in the Capitol building -- it's a sign that Muslims have a place in government and are respected, just like any other religious group or philosophy," said Williams, 33, an assistant to a Democratic congressman.
On weekdays, two of the five sets of Muslim daily prayers fall during Williams' working hours. So he washes and prays in the office with his chief of staff, a fellow Muslim.
This free use of federal offices for religious observance distinguishes the Capitol from parliaments in other democracies.
"That stands in stark contrast to every other industrialized country on the planet," said Michael Lindsay, a sociologist at Rice University in Texas and author of "Faith in the Halls of Power," a book on the rise of evangelical Christians in political life.
"Some cynics and critics can say well, these politicians are just using religion as a way to either curry favor with voters or to get political advantage," he said.
"A lot of folks ... assume that they're basically strategy sessions for the religious right."
"I'm sure some of that does happen but ... my conclusion is that most of those fellowship groups and Bible studies really remain at a personal level,' he added. "There's not very much political posturing that goes on."
In July, three Christians were arrested in the Senate gallery when they noisily protested at a guest Hindu chaplain saying the opening prayer on the floor of the chamber. But for the most part, peace prevails.
Americans United, a body that campaigns for the separation of church and state, also downplays complaints about the use of the Capitol for religious meetings.
"We've come to an understanding now that public facilities like public schools and libraries are open to lots of different groups, religious and non(-religious)," said a spokesman for the group, Rob Boston.
"As long as the understanding is that everybody gets access, we should be okay."
Religion's historic prominence in US politics and the rise of the evangelical movement in recent decades may even have benefited other faiths, Lindsay concluded from his five years of research.
"Muslims today in the United States have more latitude than I think they would have if evangelicals had not been sort of leading the charge for public expression of faith," he said.
Muslim prayers in the Capitol have gone on each Friday for a decade, undiminished despite the attacks of September 11, 2001, which led to tightened security and, Williams said, hostility against Muslims.
The jummah has expanded since permission was first given for members to use a Capitol room for it in 1997, said Suhail Khan, a Republican who works for the Department of Transport and was one of the group's founders.
Around 40 men and five women from the House of Representatives, the Senate and surrounding government offices attended recently on the second day of the holy fasting month of Ramadan.
And like Capitol Hill's other religious meetings, the prayers unite both political camps.
US presidents have openly professed their Christianity, as do most of the candidates seeking nomination to run for the White House next year. Yet the framers of the Constitution wanted "a spiritual aspect to government, but not an official religion," according to Black.
When George W. Bush says "God Bless America," Williams believes, it does not exclude other monotheistic faiths.
"We don't feel alienated when President Bush talks about God, as if it's only his," he said. "We know we're talking about the same guy."