On Tuesday evening, in the republic's largest city of Nazran, the assailant fired an RPG-25 grenade launcher from a white Lada car at the house of Murat Zyazikov. The grenade failed to launch and exploded inside the car, killing the man.
"An unidentified man, presumably a local resident...died at the scene while firing an RPG-25 grenade launcher," a source in the republic's investigation committee said.
A police source earlier said that the man had been identified as 26-year-old local resident Rustam Uzhakhov.
No members of the ex-president's family were killed or injured in the attack. According to a source in Nazran, Zyazikov was in Moscow when the incident occurred.
Zyazikov, 51, served as president of Ingushetia from 2002 to 2008.
During the last months of his presidency, Zyazikov came under pressure over his failure to curb a surge in militant activity in the tiny republic, which neighbors Chechnya. Human rights groups also accused federal authorities of torture and abductions in the republic.
In August, Ingushetia gained international media attention over the death of Magomed Yevloyev, a prominent journalist who was accidentally shot dead in police custody after reportedly being involved in an argument on a plane with Zyazikov.
On October, 31, 2008 the Ingush parliament approved Yunus-bek Yevkurov as the republic's new president.