Donald Trump's campaign has claimed that four court-appointed Republican elections workers were "blocked from the process and illegally kicked out" of a poll location in Philadelphia this morning on election day.
"This is a crime, and should not happen in a fair and and secure election as promised," a campaign statement reads. "This is an unacceptable breach of public trust, undermining transparency and Philadelphia's election."
Three of the four were added back, the statement notes.
"We demand [District Attorney] Larry Krasner and election officials to immediately act and allow our poll observers into precincts," the statement adds. "Refusing to allow Republicans into the room threatens the integrity and security of Pennsylvania's elections."
Krasner, the Philadelphia district attorney, will hold a press conference to provide an election update at 10:30 local time (15:30 GMT).
JD Vance votes in Ohio, voters wait for Trump
Donald Trump's running mate, JD Vance, voted in person a short time ago in Cincinnati, Ohio.
The Republican vice-presidential nominee was seen arriving at a polling station there with his wife and their children.
He appeared to be in good spirits.
It’s a windy morning at the polling station in West Palm Beach where Donald Trump will appear, accompanied by his wife Melania, to cast his ballot in the next couple of hours.
Ordinary voters are making their way in and out, past the large bank of cameras and reporters gathered to film the former president. He is due to arrive here, vote and - we expect - deliver some remarks afterwards.
A group of employees from the adjacent school, Palm Beach Public, are sat on the adjoining wall holding US flags and - most of them - loudly proclaiming their support for Mr Trump.
One of them, Brooke Kennedy, a teacher, says the US has been on the "wrong path" for the past four years.
She tells me that she has already voted for Donald Trump because he matches her “biblical world view” - a reminder that an amendment on whether to reverse the state's strict abortion ban is on the ballot here.
Rules on voter registration vary state-by-state, but in large parts of the US it's not too late for voters to register, even though today is polling day.
Nearly half the states, as well as the District of Columbia, allow for same-day registration on election day - but, again, the exact rules can vary.
In the other states, the deadline has already passed, with the exception of North Dakota, which does not require registration.
As polls opened in Pennsylvania, I’ve been inundated with messages from voters I’ve met over the weeks and months of the US campaign, says the BBC's Bernd Debusmann Jr from Philadelphia.
One voter I've heard from is Jay Kirell, a 46-year-old Philadelphia resident. He’s a veteran, and fought in Afghanistan with the 101st Airborne Division.
I first spoke to him after the fall of Kabul in 2021, when he told me about his complex feelings in the wake of the Taliban takeover.
Like many others I’ve spoken to in the last few days, Kirell says he’s “exhausted” by the election.
“The whole process lasts so long, and feels even longer,” he tells me. “I think everyone just wanted it to be over.”
“It’s certainly exciting,” he adds. “But exciting in the way running from a bear is exciting. You just wish it didn’t feel so life or death.”
Kirell predicts a Harris win, both in Pennsylvania and nationally. As a veteran, he says he wants a president who will do more for former service members, and navigate tricky situations in Ukraine and the Middle East.
Ultimately, he believes the election is "fundamentally two different Americas being fought for".
"And we’re 24 hours away from finding out which one we’re going to be, and absolutely nobody knows what’s going to happen," he says. "That’s utterly terrifying."