[Warning: some video scenes may be distressing to some viewers]
Video footage shows the duo taking shelter beside a car, as smoke rises behind them, seemingly from a device that has failed to detonate. Seconds later a bomb goes off in a ball of orange flames. The duo are then no longer visible.
The bomb was one of six set off by militants, in a plot that included attacks near a Starbucks cafe and the Sarinah shopping mall near the presidential palace and a number of gun-fights. Other explosives were set up near the United Nations offices in central Jakarta, along with three others in the Cikni, Silpi and Kuningan neighbourhoods, near the Turkish and Pakistani embassies.
Police said a further 10 people were injured in the attacks, which followed recent warnings of action from the Islamic State (IS).
General Anton Charilyan, a national police spokesman, said the attacks involved an unknown number of assailants with grenades and guns. He said they "imitated" the recent terror acts in Paris, on November 13 in which 120 people were killed, and were likely from IS, but gave no evidence.
No one immediately claimed responsibility for Thursday's attack on Thamrin Street, however, Aamaq, a news agency affiliated with IS, quoted an unidentified source as saying the militant group carried out the attack.
"A source to Aamaq: Fighters from the Islamic State carried out this morning an armed attack that targeted foreigners and the security forces tasked with protecting them in the Indonesian capital Jakarta," it said.
President Joko "Jokowi" Widodo said on local television: "This act is clearly aimed at disturbing public order and spreading terror among people."