General transportation strike brings much of Brazil to halt

Presidential guards stand outside the Planalto presidential palace ahead of tomorrow's general strike in Brasilia, Brazil, Thursday, April 27. 2017. On Friday, transportation unions that oversee the subway, buses and airports are calling a general strike to protest pension and labor changes being pushed through Congress by Brazil's President Michel Temer. (AP Photo/Eraldo Peres) (The Associated Press)

A worker sets up a barrier outside the National Congress ahead of tomorrow's general strike in Brasilia, Brazil, Thursday, April 27, 2017. On Friday, transportation unions that oversee the subway, buses and airports are calling a general strike to protest pension and labor changes being pushed through Congress by Brazil's President Michel Temer. (AP Photo/Eraldo Peres) (The Associated Press)

Signs with the Portuguese message "28 general strike" cover a bus stop near Planalto presidential palace in Brasilia, Brazil, Thursday, April 27, 2017. On Friday, transportation unions that oversee the subway, buses and airports are calling a general strike to protest pension and labor changes being pushed through Congress by Brazil's President Michel Temer. (AP Photo/Eraldo Peres) (The Associated Press)

Buses, trains and metros have been halted across much of Brazil as a general strike kicks off.

Transportation unions and several other groups are protesting changes to labor laws and the pension system being considered by Congress.

Police in Sao Paulo used tear gas Friday morning to break up protesters blocking roads to Congonhas International Airport. It's not shut down, though protesters are attempting to block access to airports in several cities.

Protesters at Santos Dumont Airport in Rio de Janeiro created confusion by running through the terminal and pushing down the line dividers at check-in counters.

President Michel Temer and other conservative politicians have threatened to dock the pay of public workers who don't show up.