BUENOS AIRES, Argentina (AP) — Gunmen threatened Argentine soccer superstar Lionel Messi in a written message left Thursday when they opened fire at a supermarket owned by his in-laws in Argentina, police said.

Nobody was injured in the early morning attack, and it was unclear why assailants would target Messi or the Unico supermarket in the country’s third-largest city of Rosario, owned by the family of his wife, Antonella Roccuzzo.

The city’s mayor, Pablo Javkin, went to the supermarket and lashed out at federal authorities over what he called their failure to curb a surge in drug-related violence in Rosario, located about 190 miles (300 kilometres) north-west of the capital of Buenos Aires.

Police said two men on a motorcycle fired at least a dozen shots into an Unico branch in the early hours, leaving a message on cardboard that read, “Messi, we’re waiting for you. Javkin is also a drug trafficker, so he won’t take care of you.”

Messi has not commented. Considered by many to the greatest soccer player of all time, Messi is revered in Argentina, especially since he led the national team to the country’s first World Cup victory in 36 years in Qatar in December.

Messi currently plays for Paris Saint-Germain and spends much of his time overseas, though he often visits Rosario where he has a home in the suburb of Funes. The French team posted a photo on social media of Messi training on Thursday morning.

In Rosario, prosecutor Federico Rébola said authorities were reviewing security camera footage and that the investigation was “preliminary”. It was the first time Messi’s in-laws had received this kind of threat, he added.

Celia Arena, justice minister for Santa Fe province, where Rosario is located, said the attack amounted to “terrorism” by a “mafia” group meant to intimidate the broader population.

“The aim is to deliberately cause terror in the population and discourage those of us who are fighting against criminal violence, knowing that it will be an event of global significance,” Arena wrote in a social media post.

Javkin, a centre-left politician in opposition to the ruling Peronist coalition, appeared to throw suspicion of complicity for the attack on both criminal gangs and federal security officials.

“I doubt everyone, even those who are supposed to protect us,” Javkin said in an interview with a local radio station.

He said that he had recently had “very strong discussions” with members of the federal security forces over the past couple of weeks demanding that they crack down on the city’s crime.

“Where are the ones who need to take care of us?” Javkin said. “It’s clear that those who have the weapons and have the possibility of investigating the criminals aren’t doing it, and it’s very easy for any gang to carry out something like this.”

The federal government’s Security Minister Aníbal Fernández said drug-related violence was not a recent phenomenon in the city, and that Thursday’s attack was typical of what has happened there “for the last 20 years.”

He said the incident was an example of how drug traffickers “have won” in Rosario, but now “we have to reverse that.”

Opposition politicians blamed President Alberto Fernández’s administration for the continuing violence in Rosario. His predecessor, Mauricio Macri, characterised the events as a warning that the country cannot “co-exist” with drug traffickers.

Messi, 35, is currently renegotiating a contract with Paris Saint-Germain that ends this year amid speculation that the soccer superstar could decide to end his career playing for one of the local Rosario clubs, Newell’s.

Messi, who this week won FIFA’s best men’s player award, could travel to Argentina later this month to join the national squad in playing two friendly matches. One takes place March 23 against Panama in Buenos Aires, while the other one will be five days later against Curacao in the northern city of Santiago del Estero.