Riot police react to petrol bombs thrown by masked youths in Syntagma Square during a 24-hour general strike against planned pension reforms in Athens, Greece, February 4, 2016. [Photo/Agencies]

ATHENS - Greece came to a standstill on Thursday during the first 24-hour general strike of 2016.

The mobilization was organized by labor unions in protest of the pension system reform the government is currently discussing with lenders as a prerequisite for the disbursement of further loans to Athens.

It was one of the most impressive anti-austerity mobilizations since 2010, according to local media commentators. More than 60,000 protestors, according to police estimates, participated in the rallies in central Athens, marching peacefully to the parliament, as public services nationwide were paralyzed.

Schools and courts remained closed, hospitals ran on emergency personnel and mass transportation services were disrupted. Ships remained docked at ports and dozens of domestic flights were cancelled.

The walkout, which was called by the umbrella unions of private and public sector employees GSEE and ADEDY, is the largest mobilization the Left-led government has faced a year after taking office, local analysts commented, as a wide range of professionals hit the streets in an escalation of a new round of protests that started this autumn.

On Thursday, lawyers marched next to farmers who sent delegations to Athens, as they continued their protests across the country for a third week by blocking national highways junctions and border crossings in northern Greece for several hours each day.

Civil engineers, doctors, pharmacists, taxi drivers, owners of cafeterias, petrol stations and funeral offices have also joined Thursday's rally which ended in scuffles between hooded anarchists and police.

A reporter of the Athens 9.84 municipal radio was slightly injured by a group of anarchists who attacked him while he was covering the rally, police said.

The general strike was the third the government of Prime Minister Alexis Tsipras faces in four months. The ruling radical left SYRIZA party which strongly supported anti-austerity protests in the past has issued a statement urging people to participate in the mobilizations to "assist the government in negotiations with lenders."

The strike was held as cabinet ministers and representatives of lenders who returned to Athens on Monday were discussing the government's controversial planned pension system reform, a key element to conclude the first review of Greece's new third bailout program which was sealed in the summer of 2015.

According to government sources, in order to ensure the sustainability of the system, creditors push for reductions of pensions up to 30 percent, while the government opts for a 1.5 percent raise of contributions to funds.

The goal is to save at least 1.8 billion euros ($2.02 billion) this year from the pension reform under bailout commitments.

Unions protest that the proposals on the table in combination with promoted new tax hikes will further "cripple" the real economy and Greek society instead of supporting efforts to restore growth after six years of harsh austerity that has fuelled recession.

Political analysts warned that the pension system reform will be the biggest challenge Tsipras' government will face in parliament in coming weeks. The ruling coalition controls a slim majority of 153 seats in the 300-member strong assembly and several SYRIZA MPs were under pressure from their voters to cast ballots against party line.