About 5,000 people marched in protest of immigration reform Monday morning in Detroit, according to Local 4.

The protesters are opposed to a bill that proposes tougher immigration laws, including making it a felony to be an undocumented immigrant or assisting one, Local 4 reported. The House has already passed a bill, which also authorizes more border fencing.

While the protesters marched toward the federal courthouse in downtown Detroit, police closed roads along their route. Eastbound Michigan Avenue from Rosa Parks Boulevard to downtown Detroit, and Vernor from Interstate 75 to downtown were closed just before noon, according to Local 4 reports.

The group also held its protest in front of the WDIV-TV studios on Lafayette Boulevard, which is located near the federal building that houses offices of U.S. Sens. Carl Levin and Debbie Stabenow, Local 4 reported. The protesters carried flags from the United States and from countries of their origin.

"What crimes have they done? They are the hardworking people that are essential to this economy. And if they are deported, what would happen to our economy?" asked protester Sister Julie Slowik of St. Anne's Church. "Secondly, anybody who would be helping the undocumented people in any way -- service agencies, churches -- with food, clothing, medical help, any humanitarian help, would also be considered felons."

Slowik added that the measures are "unquestionable for our country to even think of" with its long history of human rights.

Police said that the march has been peaceful. There was no information available as to how long the protest would continue Monday.

Surveys: U.S. Thinks Illegal Immigration Is Serious Issue

Most people in the United States think illegal immigration is a serious problem, according to Local 4.

A solid majority oppose making it easier for illegal immigrants to become legal workers or citizens, according to the station's reports.

Some findings in recent polling found:

Some 59 percent say they oppose allowing illegal immigrants to apply for legal, temporary-worker status, according to an NBC News-Wall Street Journal poll.

More than six in 10, 62 percent, say they oppose making it easier for illegal immigrants to become citizens, according to a Quinnipiac University poll. Nine in 10 in that poll say they consider immigration to be a serious problem, with 57 percent of those polled saying very serious.

Stay with Local 4 News and ClickOnDetroit.com for the latest developments.