The minister, General Edward Katumba Wamala, who was chief of the defense forces between 2013 and 2017, came under fire while driving in Kampala, said government spokesman Chris Baryomunsi.

"There was an attempt on his (Wamala's) life this morning ... His daughter and bodyguard were shot and they died at the scene," Baryomunsi told AFP Tuesday.

"General Katumba has been rushed to hospital with bullet wounds and he is receiving treatment, the crime scene has been taken over by the investigators," he added.

"This could be a case of assassination by criminal elements but the investigations will establish the motive and those behind" the attack.

Witnesses to the attack told local television stations that four masked men riding two motorbikes fired scores of bullets at Wamala's vehicle.

Images from the scene showed Wamala's car -- an official army vehicle easily identified by its distinctive military green number plates -- riddled with about a dozen bullet holes in the rear and driver side of the vehicle.

Tuesday's shooting is the latest in a series of attempted killings of high-profile targets by motorcycle-riding assassins in Uganda's capital.

In June 2018 Ibrahim Abiriga, a leading politician from the ruling National Resistance Movement party, led by President Yoweri Museveni, was gunned down alongside his bodyguard in similar circumstances.

In March 2017 witnesses described four masked assailants riding two motorcycles firing a hail of bullets at Uganda police spokesman, Andrew Kawessi, who was killed near the site of Wamala's murder.

In March 2015, Joan Kagezi, a prosecutor in charge of investigating a jihadist attack in Kampala in 2010, was shot dead by men on motorbikes as she returned home.

No one has been convicted of any of those killings.