Spectators had to wait for hours at security checkpoints to enter venues, while outside shootings and bomb scares kept visitors on edge.
A dazzling ceremony lifted the curtain on the Rio Olympics on Friday, but as the summer games got underway, spectators encountered problems arising mainly from security issues and the measures taken in this regard by organisers.
Fans had to wait for hours at checkpoints to enter venues, while outside, shootings and bomb scares kept visitors on edge.
Spectators leaving the Olympics opening ceremony at the famed Maracana Stadium on Friday night seen the body of a 22-year-old man who was shot dead by police in the street.
Police said the man had robbed several people in the area, but did not give further details.
A 51-year-old Brazilian woman was also shot dead during a robbery on Friday in the renovated "Marvelous Port" area meant to be a main attraction for Olympic tourists.
This came a day after police confirmed that a man sitting in a car had killed a suspect who tried to carjack his luxury automobile in the main Olympic area of Barra.
A bomb squad on Saturday carried out a controlled explosion of an unattended bag near the finish line of the men's cycling road race on Copacabana's sweeping boulevard.
It was earlier believed that the bag belonged to a homeless man.
There have been several controlled blasts in recent days as organisers have tightened security around venues amid concerns the Games could be a target for militants.
Brazil detained 12 people for suspected links to DAESH terrorist group last month.
It says the risk of an attack is minimal, with authorities having deployed 85,000 police and military to guard the Games - roughly twice the number at the 2012 London Olympics.
Lorie Schmetterling, who traveled from Moorestown, New Jersey with her husband Eric to cheer on their daughter Laura, a US rower, was disturbed to learn about the bomb scare a few hundred meters from where she was staying.
"You hear all these terrible things about how it's going to be and then you get here and it seems fine," she said.
"Then this happens and you feel it, you go on high alert again."
Journalists covering equestrian events in the Deodoro Olympic zone got a fright on Saturday when a stray bullet cut through the plastic roof of the equestrian media center.
The bullet flew above the head of the New Zealand team's media attache, according to the team's chef de mission, Rob Waddell.
No one was injured in the incident.
Police are still trying to discover who fired the bullet and from where, a spokesman for the Rio 2016 organising committee said.
A stray bullet, an exploded backpack, an anxious police force, a "gobsmacked" photographer. How's that for Day 1? https://t.co/A5E2CEt1zO— Adam Kilgore (@AdamKilgoreWP) August 6, 2016
Other robberies and thefts have targeted tourists and media in Rio.
Some 500,000 foreigners are expected to pass through the city during the Games that run until August 21.
Three Swedish tourists were briefly kidnapped on Wednesday by an armed man as they pulled off on a highway near a slum to take photos.
They were quickly released unharmed after the gunman checked the photos they took.
Drug gangs in Rio do not allow anyone to take photos or videos of the areas in which they operate, for fear of having their faces seen by police.
Security clearance, fans' queues
Athletes competed in front of empty stands early on the first day of full competition as spectators complained of missing their events while queueing for security clearance.
The queue to get through security into the main Olympics park in Rio. Getting used to Brazil time pic.twitter.com/oidNGmzHAI— Dale Miller (@miller_dj) August 3, 2016
Only a few hundred spectators made their way into venues such as the gymnastics arena and the beach volleyball on iconic Copacabana beach.
Outside, lines stretched for several blocks as fans stood in under the scorching sun as security staff struggled.
Organisers blamed a lack of coordination between security personnel, including the police, Games staff and private security firms.
Gymnasts performed in front of swathes of empty seats in an arena that can seat 13,500 people.
The boxing venue also had many empty seats as the first professionals in Olympics history entered the ring.
"I don't believe it. It's absurd, ridiculous," said Rio resident Natalia Carvalho, 28, who missed seeing Brazilian gymnast and medal hopeful Arthur Zanetti compete on the rings as she waited with thousands of others to enter the Olympic Park.
"It's a lack of respect for the fan that bought tickets. It's a shame."
What should have been a celebration of the start of South America's first Olympics turned into a damage-control operation, with Games spokesman Mario Andrada vowing an immediate improvement.
"We apologise for everybody standing in line outside the venues," he told reporters.
"Within the next hours we will be in much better shape."
At the tennis center, where former world number one Ana Ivanovic played in front of virtually empty stands in the first round, fans had to wait more than 20 minutes to buy water.
Spectators encountered similar situations at the rowing and the rugby venues as temperatures hit 32 degrees Celsius (90 degrees Fahrenheit).