While the world's attention focuses on Gaza, people continue to lose their lives in Syria, where the government drops barrel bombs in civilian areas held by forces who want to oust President Bashar Assad's regime.

The crude devices, made from large oil drums, gas cylinders and water tanks filled with explosives and scrap metal, have played a devastating role in the civil war in the Middle Eastern country. The DIY weapon wasn't invented by Syria, but the term barrel bomb only became a part of Wikipedia in November 2013, more than a year after the government began using them frequently.

Enab-Baladi, a group of citizen reporters based in Syria, said in early February that 100 barrel bombs were dropped over Darayya city in one week, killing 18 people.

Over 100 barrel bombs dropped on Daraya last week, acc to Daraya's local revolutionary newspaper, Enab Baladi pic.twitter.com/NuJycrq7UW #Syria — abigail marshall (@Aemar_) February 6, 2014

Later that month, the United Nations Security Council adopted a resolution calling on all sides of the conflict to stop using barrel bombs. The Syrian government didn't listen — Human Rights Watch reported on July 30 that it has found 650 new damage sites since then consistent with barrel bomb impacts on parts of the city of Aleppo held by rebel groups. The website includes interactive images of the targeted areas before and after the bombings.

The European media director for Human Rights Watch, Andrew Stroehlein, tweeted a map of locations where the organization says the government has dropped the barrels. A list on Wikipedia also purports to show nearly 80 documented barrel bomb attacks in Syria.

#Syria govt barrel bombs civilians in defiance of UNSC: 650 major new damage sites documented http://t.co/khA8gBw9mq pic.twitter.com/c5U5Rr7y4V — Andrew Stroehlein (@astroehlein) July 30, 2014

The bloody battle for control of Syria between forces loyal to President Al-Assad and the factions that are opposed to his rule entered its third year in March. More than 170,000 people have been killed in the conflict, which began with anti-government protests during the wave of Arab Spring demonstrations across the region.

The U.N. and human rights organizations have accused the government of launching indiscriminate attacks on civilians. Rebel groups have also faced the same accusation, but the Assad regime is unique in its use of barrel bombs.

On well-known blog Brown Moses, who has followed the Syrian civil war closely, Richard M. Lloyd, a warhead technology consultant at Tesla Laboratory Inc., examined the barrel bomb technology in a December 2013 post:

[…] The main objective of the Syrian barrel bomb program is to provide cheap and lethal damage on urban areas in Syria. […] These early barrel bomb weights are around 100-300lbs (45-140 kg) and are ignited using fuse wicks. The soldier lights the fuse wick using a cigar because the wind would blow out a match or lighter. […] The single-shot bomb probability of success is 37.5%, which means it would require five bombs to achieve one successful explosion. […] The Syrian government over the last year has significantly increased it's barrel bomb sizes from hundreds of pounds of explosive to 2000 pounds (900 kg) of explosive.

The video below posted by group SyrianZero on YouTube, subtitled in English and translated to Arabic, reportedly captures the moment when an Assad helicopter drops a barrel bomb on Darayya in January 2014. The footage also shows a rescue operation of one man trapped in rubble and rebels who threaten Assad with revenge [Warning: Graphic video, viewer discretion is advised.]

