Dozens of protesters armed with guns have pushed their way into Michigan’s state house as politicians debated an extension to coronavirus lockdown laws.

The protesters were part of a group of up to 700 who had gathered for the “American patriot rally” at the state house’s forecourt to show their opposition stay-at-home orders imposed by Governor Gretchen Whitmer.

Scores were allowed into the government building in the state capital, Lansing. State police spokesman Lieutenant Brian Oleksyk said the protest was peaceful.

“They were chanting peacefully and that was it,” he said.

However, several protestors were forcibly removed by security guards. One was carried out on a stretcher.

State senator Dayna Polehanki tweeted that protesters were directly above her, “men with rifles yelling at us”.

“Some of my colleagues who own bullet proof vests are wearing them. I have never appreciated our sergeants-at-arms more than today,” she added.

Tweet from @SenPolehanki

Michigan has been a hotbed for anti-lockdown protests. Ms Whitmer, a Democrat, has angered Republicans by instituting some of the US’s strictest social distancing measures.

On Thursday, the Republican-led house voted to sue her to challenge her authority in combatting the pandemic.

Michigan’s state of emergency was to expire at the end of Thursday. But on Friday (local time), Ms Whitner signed executive orders to extend it to May 28, having already extended an earlier stay-at-home order until May 15.

“While some members of the legislature might believe this crisis is over, common sense and all of the scientific data tells us we’re not out of the woods yet,” she said.

“By refusing to extend the emergency and disaster declaration, Republican lawmakers are putting their heads in the sand and putting more lives and livelihoods at risk.”

But organiser Ryan Kelley, a real estate agent, described the protest as a triumph.

“This was a huge win,” he said.

Protesters at the “American patriot rally” in Michigan. Photo: Getty

Despite the protests, polls have shown broad approval for Ms Whitmer’s response to COVID-19. In April, a Detroit Regional Chamber poll found 57 per cent of Michigan residents in favour, compared to 37 per cent who were not.

By Thursday, the state had more than 41,000 cases of coronavirus and nearly 3800 deaths.

Across the US fatalities are nearing 60,000, but there are growing calls to reopen businesses. Nearly 30 million people have lost their jobs in the past six weeks.

Tesla chief executive Elon Musk this week described stay-at-home orders as “forcibly imprisoning people in their homes … against all their constitutional rights”.

US President Donald Trump has said he will not extend social distancing rules when they expire this week.

He also sparked anger in April with a series of tweets aimed at Democrat governors who had imposed lockdown orders, including Ms Whitner.

Tweet from @realDonaldTrump

Elsewhere, Mr Trump will leave the White House for the first time in a month when he travels to the Camp David presidential retreat in Maryland.

The President will make the 40 kilometre trip on Friday night (Washington time), the White House said on Thursday.

Mr Trump’s last trip away from the White House was on March 28 to Norfolk, Virginia. He went there to farewell the Navy’s USNS Comfort hospital ship as it sailed to New York City to help take the pressure off civilian hospitals.

Mr Trump, who faces re-election in November, said on Wednesday he would visit Arizona next week for an “industry”-related event.

-with AAP