GENEVA, Switzerland (AFP) — United Nations experts called Saturday for impartial investigations into allegations of “undue interference” of protests seeking to draw attention to Mexico’s disappearance crisis during the football World Cup.

Security operations around tournament venues were reportedly used to restrict protests, the six independent experts said.

Protesters had in some instances been surrounded by police while peacefully distributing search notices for their disappeared relatives, while other groups were allegedly prevented from reaching planned demonstrations, they added.

“We are concerned by reports of incidents in which families searching for disappeared loved ones reportedly faced interference whilst peacefully making their voices heard during one of the world’s largest sporting events,” said the experts.

“International sporting events should never come at the expense of civic space or the rights of victims.”

Activists and families searching for their loved ones had sought to organise a range of peaceful demonstrations, symbolic actions and public awareness activities around World Cup events.

The aim, said the experts, was to “draw international attention to the country’s high number of disappearances and to reiterate their demands for truth, justice and reparation”.

About 130,000 people have been officially recorded as missing in Mexico since 2006, when the then government launched its controversial anti-drug operation. Some experts say the real number could be even higher.

In their statement Saturday, the experts, who are mandated by the UN Human Rights Council but who do not speak on behalf of the United Nations, said: “States have an obligation to guarantee the right to freedom of peaceful assembly and expression.”

The experts, including members of the UN working group on enforced or involuntary disappearances, said peaceful protesters had reportedly faced interference, intimidation and online harassment.

Major events like the World Cup “naturally attract global attention, creating a vital window of expression for social movements, civil society organisations, and local populations to vocalise systemic local, national or even global problems,” the experts said.

“We call on authorities to ensure that families of disappeared persons can peacefully exercise their rights,” they said.

They also demanded that “allegations of undue interference are promptly and impartially investigated and that effective measures are taken to protect those who continue searching for their loved ones”.