The protesters took to the streets in the capital Athens on Thursday, Reuters reported.
Thousands of police officers and coast guards from various Greek regions marched to parliament to protest against salary cuts expected to be included in a new austerity bill.
Next week, Greek Finance Minister Yannis Stournaras is likely to send the parliament a bill of labor reforms, which includes the officers' salary cuts.
In protest to the cuts, the police officers and the coast guards also handed out bowls of bean soup to the needy.
"[We say] 'No' to modern slavery. Our rage is overflowing. They lied to us again; those pre-election promises became dust after the elections, and will lead us to new medieval times," said Dimitris Sarantakis, the president of the Panhellenic Coast Guard Officers' Federation.
"Even if these measures pass the way they have arranged them, we will overturn them because we have not only reached our limits, we have now surpassed our limits," said Dimitris Vogiatzis, the president of the Police Officers' Federation.
A large number of Greek firefighters chanting anti-austerity slogans also marched on the parliament.
Earlier in the day, public hospital staff including doctors, nurses and ambulance drivers, walked off the job and staged a demonstration outside Greek Health Ministry headquarters. They said austerity cuts have weakened citizens' health and made their jobs more difficult.
They carried banners reading, "Austerity measures are bad for your health" and "Free public health care for all".
Greece has been at the epicenter of the eurozone debt crisis and is experiencing its fifth year of recession, while harsh austerity measures have left about half a million people without jobs.
One in every five Greek workers is currently unemployed, banks are in a shaky position, and pensions and salaries have been slashed by up to 40 percent.
Greek youths have also been badly affected, and more than half of them are unemployed.
Also on Thursday, a Greek court ruled that some of the spending cuts needed to secure more bailout funds for the near-bankrupt country are unconstitutional.
The Court of Auditors, which examines Greek laws before they are presented to parliament, said planned austerity measures such as raising the age of retirement to 67 and reducing pensions by 5 to 10 percent, could be against the constitution.
The court said the pension cuts for a fifth time since May 2010 violated many constitutional provisions, including the principles of individual dignity and equality before the law.