For months, Greeks have been upset over austerity measures to head off a catastrophic default, but a massive 24-hour strike Wednesday revealed a new level of anger and frustration in the country.

Riot police clash with demonstrators during a protest rally marking the 24-hour general strike Wednesday. (Louisa Gouliamaki/AFP/Getty Images)

At least 16,000 protesters gathered in central Athens on Wednesday, and 10,000 more gathered in the northern city of Thessaloniki.

Although most were peaceful, a few dozen protesters near parliament clashed with riot police. Ten people were arrested and two officers injured.

Dozens of businesses and government services were forced to shut after no employees showed up to work. Disruptions included:

1. Public transport.

Civil servants simply walked off the job, protesting plans to suspend about 30,000 staff on partial pay.

2. Flights

Air traffic controllers joined the 24-hour strike, grounding all flights to and from Greek airports.

3. State television and radio.

News programs have simply been pulled off the air.

4. State hospitals

Hospitals are running on emergency staff.

5. Private-sector employees

Lawyers and teachers didn’t go to work.

6. Journalists

Although journalists have gone to work, several of them, including an AFP and a local photojournalist, have been punched by police while covering the protests.

A riot policeman punches Greek photojournalist Tatiana Bolari during a demonstration in Athens's Syntagma square Wednesday. (Yannis Behrakis/Reuters)

Greece has relied on a $145 billion package of international bailout loans since May 2010, but it since hasn’t met budget targets required to qualify for the funds.

The economy is expected to contract 5.5 percent this year, and unemployment has skyrocketed to above 16 percent.