RIO DE JANEIRO (AP) — A violent police strike in northeastern Brazil has shed light on dissatisfaction among cops elsewhere in the country, with some forces threatening to protest as rowdy Carnival celebrations start.

The strike by military police demanding higher salaries in the state of Ceara, and which led to a senator being shot, is a headache for President Jair Bolsonaro, a staunch supporter of police forces who has pledged to curb violent crime.

“Of course, police strikes could spread,” said lawmaker Guilherme da Cunha of the state of Minas Gerais, where police obtained a 42 percent salary increase this year after threatening to strike. “From the moment people who have a monopoly on firearms discover the strength it has, there is a risk.”

In Ceara, violent crime has risen sharply during the police strike, with at least88 people killed overthree days, accordingto online news site G1, citing state officials. Bolsonaro has sent hundreds of national guard forces and 2,500 soldiers to maintain order.

During the strike, Sen. Cid Gomes was shot in the chest as he tried to drive a backhoe through a police protest. He is in stable condition. Earlier that day, masked officers forced businesses to close, occupied barracks and damaged police vehicles.

Mayors in several of the state’s small cities — 30,000 inhabitants or less — canceled Carnival celebrations. In Paracuru, where authorities were expecting 40,000 revelers a day, the mayor said he was no longer able to ensure security in his city’s streets.

Even though police strikes are illegal in Brazil, other states are at risk of seeing similar protests, lawmakers and public security experts told The Associated Press.

In Alagoas state, civil police, in charge of investigating crimes, have been on strike for two weeks.

“The governor has made a lot of empty promises to the military police. At some point, that bomb can explode,” said lawmaker Davi Maia, who has met police in Congress to discuss their demands.

In Paraiba, military police organized a 12-hour strike on Feb. 19. In Santa Catarina, public security agents threatened to slow work to a bare minimum, paralyzing operations to an extent but avoiding illegal strikes.

In Rio, one association of municipal guards, who police city parks and properties, began a strike Saturday, during Carnival.

Police strikes aren’t new, according to Ilona Szabó, co-founder of a security research center, the Igarapé Institute. A study by the Federal University of Rio Grande do Sul showed that between 1997 and 2017, Brazil had 715 police strikes, but only 52 by military police.

“More than ever Brazil needs to democratize and professionalize its police forces,” Szabó said.

Many believe police officers are emboldened by the 2018 elections, in which Bolsonaro and other fervent law-and-order supporters were elected. A former army captain, Bolsonaro supported the armed forces during his 30-year legislative career and has said police who kill on duty should be decorated.

Many Brazilians states’ finances are in the red, with public servants often receiving partial or delayed salaries. Carnival celebrations often prove a good opportunity for public servants, including police, to pressure authorities, who fear violence and looting during the festivities.

Tourists and party-goers at Carnival are often targeted by pick-pockets. In the state of Sao Paulo, police have arrested 240 suspects as part of a carnival security operation.

Last year, public security officers in Minas Gerais also chose February to threaten the newly elected administration of Gov. Romeu Zema Neto with strikes if he didn’t readjust their salary.

“The government was pressured to choose between a terrible, and least worst option,” said state lawmaker da Cunha. Police shut down a motorway and armed men attempted to invade the governor’s office, according to witnesses who asked that their names not be used because of safety fears.

As part of the negotiations, the governor obtained an agreement that the increase be postponed one year, meaning the proposal only landed this month in the state’s legislative assembly.

The news of a 42 percent salary increase spread rapidly, boosting similar requests in Ceara and other states, and angering governors who have resisted threats of illegal protests.

“Minas Gerais granted this increase, in a state that is not paying salaries, and is in a situation of bankruptcy,” said Ignacio Cano, coordinator of the Violence Analysis Laboratory at the State University of Rio de Janeiro.

“It says a lot about the moment the country is going through, and the strength that public forces are acquiring,” he said.