DALLAS (AFP) -- Nearly 53 years after president John F. Kennedy was assassinated while riding in a motorcade through the streets of Dallas, the bustling Texas city is reliving the nightmare of a murderous sniper.

Just 200 meters separate El Centro College, where shooter Micah Johnson set up an ambush to shoot at police late Thursday, and Dealey Plaza, where Kennedy was shot dead on November 22, 1963 while sitting in an open-air limousine.

Mere steps away from the police tape cordoning off the crime scene lies the Texas School Book Depository, now known as the Dallas County Administration Building -- from which Lee Harvey Oswald took aim at Kennedy and shot at him with a rifle from the sixth floor.

The Sixth Floor Museum, housed inside the building and dedicated to Kennedy‘s life, death and legacy, was closed on Friday.

“They were setting a crime scene investigation. Access to Dealey Plaza was going to be restricted and I think given the fact that it’s a tragic event for Dallas, it didn‘t seem right to have the museum open,” said the museum’s longtime executive director Nicola Longford.

It reopened on Saturday, posting words of support on its website for the families and colleagues of the five police officers killed, and seven officers and two civilians wounded.

“We encourage you to ... share personal reflections during this trying time,” the message read.

While both killings took place at the hands of a sniper shooting on unsuspecting victims, Longford stressed that the two tragedies that have rocked the city are quite distinct and otherwise share no parallels.

“This is one of those moments that is going to test all of us. Dallas, our home, is about to become famous again for all the wrong reasons. It‘s going to be a shorthand for chaos,” wrote Jacquielynn Floyd, a columnist for The Dallas Morning News.

“It furthers no cause; it accomplishes nothing but misery and grief. It’s violence for the deranged love of violence itself, disguised beneath a political veneer.”

Jamie Najera, a young mother who was not even born when Kennedy was shot, said: “Immediately I linked the two together in my mind.”

Kennedy‘s assassination “became that much more oppressive to me,” she added.

The assassination has long weighed over Dallas, even if the city was more witness than actor in the tragedy.

“This is a site for reflection and contemplation about a historic event that affected the world,” Longford said.

“They’re still living to some degree with the consequences of what happened 53 years ago, but we‘re not making comparisons. I don’t think it‘s appropriate.”

James Garrett, a homeless man who gives tours of Dealey Plaza, said many of his tourist customers “feel like it’s a tragedy and they still don‘t understand why it happened here.”

“If you can get away with killing the president, we’re not safe,” he added.

Even if the gunmen‘s ambush tactic is the only common element in both shootings, death once again has landed Dallas at the top of headlines around the world.

An increasingly frustrated President Barack Obama, who has had to address senseless killings time and again during his term that began in 2009, his calls for gun control going unheeded in a Congress led by his Republican foes, is due in Dallas early next week.

“I’m sure there‘s a little bit of embarrassment on their part and unfortunately this is not the way they want to be in the limelight,” John Priesta said of Dallas officials.

Priesta, visiting from Nebraska, remembers clearly when Kennedy was assassinated. He was only eight years old at the time.

The city itself has been transformed in the years that have since elapsed.

A huge project launched in 2011 has revitalized the downtown area, including new skyscrapers housing offices, startups and thousands of

residential facilities.

The huge Klyde Warren Park opened in 2012 above a freeway that cut through the city, in an echo of other cities like Boston or Seattle.

Dallas, which in 1963 was considered a conservative bastion, today is a progressive city led by a Democrat, Mike Rawlings.

“Dallas should be known as the city of opportunities,” said Navera, who emigrated from Mexico when she was eight years old.

Dan Bradley, who runs the Bullzerk gift shop in the hip Lower Greenville neighborhood, had “Unite Dallas” T-shirts made after the shooting.

Half of the proceeds of the sales will go toward a foundation supporting officers’ families.

He sold 300 in just a few hours, and orders keep flooding in.

“There‘s so much diversity and different kinds of people here, with the same end goal, being very successful and work,” said Bradley.

Longford was confident that Dallas would bounce back from the tragedy, just as it did after the Kennedy assassination.

“Dallas is a very forward-looking city and this is just a tragic event that put us all in shock. But we will move forward,” she said.