BSS/AFP) - Mexican President Claudia Sheinbaum said on Monday she could guarantee a peaceful World Cup opening ceremony this week, despite concern over ongoing protests.

A teachers union has threatened demonstrations at Thursday`s opening game between Mexico and South Africa in the capital if the government doesn`t respond to demands for salary raises and pension reforms.

"We are going to guarantee... that the celebration of the World Cup is well-executed, in peace and tranquility," Sheinbaum said in her daily press conference.

Last week, police dispersed protesters with teargas and rubber bullets outside the historic Zocalo square where authorities have erected a massive screen for a World Cup fan zone.

The streets surrounding the square remain closed off with metal barricades, which Sheinbaum has said are meant to guard against "provocations."

Protesting teachers also toppled commemorative statues of players in downtown Mexico City last week.

Though Sheinbaum has maintained open dialogue with the teachers, the union has deemed government proposals insufficient.

Joining the protests are hundreds of people from the Ayotzinapa teachers college, who are demanding further efforts to investigate the disappearance of 43 students from the rural school in 2014.

Mexico City police said they discovered 59 homemade explosive devices on one of the bus convoys entering the capital on Monday, posting a photo of dozens of small white pipes with fuses on X.

- Tourists `freaked out` -

The teachers` sprawling tent camps have flooded the city center, leading to complaints from businesses that tourists will stay away during the World Cup.

"The access to our restaurant is closed off, the people aren`t coming, the tourists are freaked out," 31-year-old waiter Jonathan Herrera, who was protesting against the encampment, told AFP.

Around 50 people waited to cross through one of the metal barricades under the watch of police, where one restaurant glued a poster reading "we`re still open."

US tourist Heather Lutz, 64, expressed support for the protesters.

"No government likes their city to look real" during big events like the World Cup, she said.

The tournament is the ideal moment to "generate pressure" to win concessions from the government, 42-year-old teacher Dinora Diaz told AFP in the street encampment.

- Negotiations -

Sheinbaum`s government explained on Monday their proposals to the teachers union, proposing the creation of a new state-owned company to administer pensions.

But the government dismissed the possibility of reversing pension laws, arguing it would cost around $400 million.

The teachers have rejected the government`s proposals while the Secretary of Governance Rosa Icela Rodriguez called for the strikers to lift the blockades.

"It`s fundamental that the legitimate exercise of the right to protest can coexist with the rights of those who live in and move through this great city," the official said.