Images of daring graffiti adorning the walls and buildings of Tehran have gone viral on Facebook and Twitter.

The street art, which offers timely social commentary on the events in Gaza and life in Iran, is the work of an anonymous artist or group of artists known as Black Hand, dubbed the “Iranian Banksy” by some media outlets. Graffiti is illegal in Iran, though authorities allow street art that supports the Islamic Republic. 

Black Hand's work challenges the government on its ban against women attending sporting events and fraud in the 2009 elections that saw millions take to the streets against Mahmoud Ahmadinejad's “landslide” election. Take a look at four photos of the artwork currently circulating on social media. 

1. Bleeding Gaza

Iranian graffiti artist Black Hand strikes again, this time for Gaza. pic.twitter.com/YGkJ6ySkP4

— Arash Karami (@thekarami) julio 12, 2014

In the most recent Black Hand graffiti to trend on social media, Iranians posted images of the artist's wall depiction of blood pouring over the word “Gaza” from 2012. The artist later thanked fans on Facebook for reviving the artwork in light of the renewed violence between Israel and Gaza, which has left more than 200 Palestinians dead so far. In his post, Black Hand was pleased to see that Iranians of all political stripes stood united together against Israel’s bombardment of the coastal enclave.

2. Women and sports

#Iran‘s washing up liquid protest. Black Hand is sometimes referred to as “Iran's Banksy”! http://t.co/FINwgOzP7W pic.twitter.com/bw88GP5uKK

— Saeed Valadbaygi (@SaeedBaygi) July 14, 2014

This image of a woman wearing the Iranian football team's jersey while thrusting a bottle of diswashing liquid is reminiscent of players holding up the World Cup trophy. The image appeared around the time that the team was competing in Brazil in June. Black Hand posted an image of the artwork on Facebook.

Women, including female journalists, are banned from attending football and volleyball matches in stadiums. The graffiti, which was on a main street in Tehran, was blotted out with red paint shortly after it appeared.

It's unclear whether authorities erased it or the artist did it as metaphor for the lack of female presence in sports.  

3. ‘Enough fighting, continue with diplomacy’  

Iranian #streetartist Black Hand has advice 4 #IranTalksVienna: Enough fighting, continue w/ diplomacy. (July 2013). pic.twitter.com/hNYQW6pFbr

— Sidewalk Lyrics (@pedestrian) julio 14, 2014

This depiction of boxing gloves seemingly hung up for good is accompanied with the caption, “Enough fighting, continue with diplomacy.” An image of the art started to trend among Iranian users on social media this week as nuclear negotiations in Vienna continued.

The graffiti was spotted in July 2013 as Iranians were finishing a tough political period under President Ahmadinejad during which tensions over Iran's nuclear program were renewed and sanctions took a crippling toll on the Iranian economy. Iranians elected the moderate President Hassan Rouhani in June 2013, who campaigned on the platform of diplomacy and and end to the conflict and resulting economic crisis.

4. 2009 elections  

انصافن یکی از بهترین گرافیتی هایی که تو عمرم دیدم.کار هنرمند ناشناخته ایرانی #Blackhand https://t.co/gXN3YnwP6r pic.twitter.com/IjwYBpqT1R

— Babi (@Babifrown) June 30, 2014

One of the best works of graffiti I have seen in my life. The work of a unknown Iranian artist. #Blackhand 

This June sighting became popular on social media, with simple graffiti of the link to the leaked YouTube video of Iran's Revolutionary Guard commander saying that the reformists’ return to power in the 2009 elections was a “red line” for them, deemed as the first time authorities admitted to participating in election fraud.

Then, President Ahmadinejad was reelected in the vote, but millions argued that the election was rigged. Anger over the results sparked the Green Movement, with mass demonstrations in the months that followed until an attempted rally in February 2010 was brutally suppressed.