Decoding explosives used in Tuesday’s twin blasts

A police breakdown truck tows a vehicle that was damaged by the explosion on Parliament Avenue in Kampala City on November 17, 2021. The death count from Tuesday’s twin blasts in the heart of the city has risen to seven, following an overnight death. PHOTO/DAVID LUBOWA

What you need to know:

Investigators say the IEDs that exploded in Kampala’s Komambogo suburb and on a moving bus in Mpigi District were of relatively different makes compared to the Tuesday explosives.

When two bombs exploded mid-morning on Tuesday at the Central Police Station (CPS) and on Parliament Avenue, both in Kampala, the most immediate trepidation for many was the deafening sound and tremor they caused.

The blast on Parliamentary Avenue shattered glasses of nearby high-rise buildings including Parliament, about 100 metres away, and Crested Towers, which is farther away.

While the explosion at CPS, which is less than half-a-kilometre from the south-western gate of State Lodge Nakasero, echoed horror in the leafy upscale Nakasero neighbourhood.

Both blasts generated flames, which set nearby cars and motorcycles alight, and sent thick dark plumes of smoke billowing in space.

The impregnable question was: what explosive caused such a bang, wreck and sparked fires?

Military and police forensic analysts, based on examination of fragments and other scene of crime evidence, now believe they have decoded the answer.

It is, according to the findings, a home-made Improvised Explosive Device (IED) packed with nails, ball bearing and metal pieces and in which ammonium nitrate (formed out of nitric acid and ammonia) was used as an oxidiser.

A source involved in the investigations of the Tuesday blasts said “a decayed ammonium nitrate” was used as the propellant to provide the pressure to scatter the fragments that have so far killed seven people, three of them policemen, and dozens.

Ammonium nitrate is most accessible ingredient for IED making, alongside hydrogen peroxide, because it is produced in big quantities for fertiliser and blasting in mining and other industries.

Investigators say the IEDs that exploded in Kampala’s Komambogo suburb, killing bar maid Emily Nyinaneza, and on a moving bus in Mpigi District, killing Isaac Matovu, aka Muzafaru, were of relatively different makes compared to the Tuesday explosives.

Security posthumously identified Muzarafu as an operative of the Allied Democratic Forces (ADF), a designated terrorist organisation, and said he was carrying the IED when it exploded.

The impact and damage of the October blasts were minimal unlike the horrendous bang and carnage of this week’s explosion.

“[In the explosions of] Komambogo and Swift bus, the ammonium nitrate used as the propellant was at the lower stage [of decay] … while the ammonium nitrate used [in the IEDs] that hit Kampala on Tuesday was decayed. That’s why it had strong impact and fragments,” an intelligence source said yesterday.

The police forensic team has reportedly written a report and shared it with the Joint Security Operations Committee sitting at Naguru Police headquarters, breaking down the make of the different IEDs used in the four attacks this and last month.

“We are lucky that the ammonium nitrate used was in small quantity and it had not yet decomposed a lot to become more deadly,” a senior security officer said, making assessments based on details provided in the forensic team’s report.

The source added: “We believe these terrorists haven’t mastered the entire art of using ammonium nitrate to throw the shrapnel with a lot of pressure.”

Police spokesperson Fred Enanga said he had not seen the report detailing the findings.

He said the Joint Counter-Terrorism Taskforce completed documenting evidence from blast sites and motorcycles believed to have been used by the attackers and taken body samples for DNA test. They also obtained very critical cyber leads and other digital evidence.

In the aftermath of the Tuesday attacks, police and President Museveni separately blamed ADF, a Ugandan rebel group that over the years found safe haven in eastern Democratic Republic of Congo.

About IEDS

An improvised explosive device (IED) attack is the use of a “homemade” bomb and/or destructive device to destroy, incapacitate, harass, or distract. IEDs can come in many forms, ranging from a small pipe bomb to a sophisticated device capable of causing massive damage and loss of life.

Source: United States Department of Homeland Security website