"It's a childish story that keeps repeating in the West," smiled Syrian President Bashar al-Assad, in an interview with the BBC last week. He was dismissing allegations that his regime is attacking Syrian civilians with barrel bombs, crude devices packed with fuel and shrapnel that inflict brutal, indiscriminate damage.

"I haven't heard of the army using barrels, or maybe, cooking pots," Assad said, and then repeated when pressed again: "They're called bombs. We have bombs, missiles and bullets. There [are] no barrel bombs, we don't have barrels."

If you think Assad doth protest too much, you're probably right. Human rights organizations, witness testimony and foreign governments all point to the Syrian government's frequent use of barrel bombs in densely packed urban areas, including a suspected attack last week in a devastated suburb of Damascus. The fact that it's a deliberately indiscriminate weapon of war makes the Assad regime liable for war crimes.

Here's footage, uploaded to YouTube by Syrian activists last year, of a suspected regime barrel bomb attack in the capital's environs.

Assad is not alone in allegedly using barrel bombs. Last summer, Human Rights Watch accused the government in neighboring Iraq of dropping barrel bombs in civilian-populated areas during its clashes with the militants of the Islamic State.

Look a bit further into the past, and you'll find that barrel bombs were featured in an American military campaign, too.