The US Republican convention has begun in uproar today, with a failed attempt to defy Donald Trump's nomination and a rejected police request to suspend open-carry gun rights.
Police had been tightening security in Cleveland, where New York businessman Mr Trump was set to be confirmed as the party's nominee for US president.
The convention had barely begun when anti-Trump delegates demanded a vote on the rules so they could formally voice their view that Mr Trump is the wrong man to become the party's presidential candidate.
The anti-Trump forces at the convention started shouting "roll call" after they were barred from registering their opposition.
The vote would have recorded the number of delegates who were opposed to Mr Trump's nomination.
Many delegates began demanding a roll-call vote, chanting "roll call, roll call". Others walked out of the convention hall, saying they had to assess their next steps.
A request by police for Ohio's governor to suspend open-carry gun rights earlier came from police after three officers were shot dead in Louisiana on Sunday.
Ohio's governor said he did not have the power to suspend the law, which allowed licensed gun owners to carry weapons.
Among the speakers due to appear on Monday evening were Mr Trump's wife Melania and Iowa Senator Joni Ernst, on a theme of "Make America Safe Again".
The convention would begin in a time of high tensions - a day after a man killed three police officers in Baton Rouge], prompting Mr Trump to say the country was falling apart - a claim strongly disputed by President Barack Obama.
People are not allowed to take guns into Cleveland's Quicken Loans Arena, which is hosting the four-day event, or within a secure zone outside.
- What's the point? Each party formally nominates its candidates for president and vice president, and the party unveils its party platform, or manifesto.
- Who is going? There are 2,472 delegates attending, selected at state and congressional district conventions, and representing each US state and territory. Plus 15,000 journalists and thousands of other party grandees, lawmakers and guests.
- Who isn't going? Some senior figures who don't like Donald Trump have stayed away, including two ex-presidents named Bush, former nominee Mitt Romney and Ohio Governor John Kasich.
- What's the schedule?
- Monday speakers - Melania Trump, Senator Joni Ernst, former NYC Mayor Rudi Giuliani
- Tuesday - House Speaker Paul Ryan, New Jersey Governor Chris Christie
- Wednesday - VP nominee Mike Pence
- Thursday - Donald Trump, introduced by daughter Ivanka
But some people were photographed openly wearing guns nearby.
"I don't care what the legal precedent is, I feel strongly that leadership needs to stand up and defend these police officers," said Steve Loomis, the head of the police union that was making the request.
Mr Loomis urged governor John Kasich, who himself earlier ran against Mr Trump seeking the Republican nomination, to declare a state of emergency and issue the temporary ban as protesters gathered in Cleveland a day before the four-day convention was due to begin.
Thousands of federal and state law enforcement officers have descended on the city over the past week in preparation for the convention, ramping up security protocols as delegates, attendees and demonstrators pour into Cleveland.
About 50,000 people are expected to travel to Cleveland during the four-day event, with protests and rallies expected to take place throughout the week.
Many of Mr Trump's previous campaign events have been marred by heated protests and violent outbursts across the country.
Tensions have also been high between police and protesters amid a recent string of violence, which included the police shootings of two black men as well as an attack in Dallas that left five police officers dead.
On Sunday, the violence continued in Baton Rouge, Louisiana, where a gunman shot and killed three officers and injured three others, one critically, near the city's police headquarters.