BAKU, Azerbaijan — The first European Games opened in Azerbaijan on Friday with an extravagant opening ceremony featuring Lady Gaga, although even her star power failed to dispel some of the concerns hanging over the event.

The games in the oil-rich nation’s capital Baku have become a focal point for criticism Azerbaijan’s human rights record, and worries over the competition’s sporting credibility.

They were opened by the country’s President Ilham Aliyev, who has held power since 2003 and whose regime has been accused of jailing political dissidents on trumped-up charges.

The ceremony featured all the pomp of an Olympic opening with an eclectic show combining Greek myth, a giant floating pomegranate and a video message from physicists at the Switzerland-based CERN research center.

“This spectacular celebration is the victory of independent Azerbaijan and each Azerbaijani citizen,” said Aliyev’s wife Mehriban Aliyeva, who heads the organizing committee for the games. “Dear athletes, these games are for you.”

The venue for the extravaganza was Baku’s 68,000-capacity Olympic Stadium, whose walls lit up in the colors of the Azerbaijani flag during a ceremony steeped in nationalism, including the booing of the delegation from traditional rival Armenia.

A flaming torch was carried into the stadium by Ilham Zakiyev, a two-time Paralympic gold medal-winning judo athlete who lost his eyesight when he was shot while serving in Azerbaijani forces on the front line of the conflict over the Armenian-occupied region of Nagorno-Karabakh and related territory.

That stadium will also illustrate the European Games’ struggles to establish itself as a new major sports event when it hosts a low-level track and field competition. Many sports will be of near-Olympic standard, especially combat events like boxing and wrestling, but others like athletics and swimming will not feature star names.

An element of tragedy also hung over the opening after a 15-year-old Austrian swimmer was left with serious spinal injuries when she was hit by a bus while walking in the athletes’ village on Thursday. Two teammates received less serious injuries.

The games are the brainchild of the European Olympic Committees and the organization’s president Patrick Hickey.

“We are witnessing, we are creating a landmark moment in European sport,” he said.

Hickey did not mention human rights, although he said “sport has a unique power to effect positive change” in society.

Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan were among the world leaders in attendance.

Lady Gaga’s performance was kept a secret until part-way through the ceremony, with the American singer performing John Lennon’s song “Imagine” while playing a piano covered in flowers. The singer, who wore a simple white smock as opposed to one of her signature eccentric outfits, was given a rapturous reception for her performance, which included an unusually full-throated rendition of the final verse of Lennon’s low-key classic.

“I’m extremely honored to be playing at the opening ceremony in Baku, and to be celebrating all of the amazing athletes who will compete in the European Games in this beautiful city,” she said in comments released by organizers.

Under pressure from human rights activists, Azerbaijan’s government has demanded that politics and sport be kept separate during the games. However, politics intruded into the ceremony when the athletes from Armenia, Azerbaijan’s traditional rival, were roundly booed by the crowd, who also shouted “Azerbaijan!”

Azerbaijan’s Nagorno-Karabakh region and some adjacent territory have been under the control of Armenian soldiers and local Armenian forces since a 1994 cease-fire that ended a six-year war.

Other teams were warmly welcomed, with Azerbaijan’s neighbor Turkey and fellow ex-Soviet states Ukraine and Russia receiving some of the loudest cheers – apart from the roar reserved for the host nation’s team.

“I know I have made everybody – all my friends and family back home – really, really happy and I am honored myself,” Olympic boxing champion Nicola Adams told The Associated Press earlier Friday as she prepared to be Britain’s flagbearer at the ceremony. “It’s an amazing opportunity and it is a once in a lifetime thing.”

The ceremony saw athletes from Kosovo parade for the first time under their own flag at a major games, as one of the 50 nations which have sent athletes to compete across 20 sports.

Protests against Azerbaijan’s human rights record took place in cities around the world Friday, although in Baku, where demonstrations are heavily restricted, opposition groups did not announce any protests ahead of the opening ceremony.

The day before, jailed journalist Khadija Ismayilova criticized Azerbaijan’s government, writing that the country was in a “human rights crisis” and beset by high-level corruption.

“Things have never been worse,” said Ismayilova’s letter, released by the PEN organization, which said it had been smuggled out of prison in pieces.

The games run through June 28.