Three people were killed on Tuesday during a blast inside their vehicle in October Six district of Giza province near the capital Cairo, the Egyptian Health Ministry said in a statement.
"Following up the aftermath is going on and ambulances have already rushed to the scene," the ministry noted.
Official MENA news agency reported earlier that two men were killed on Tuesday as two explosive devices in their vehicle went off near a police station in the district in Giza.
"The two men driving the car were burnt to death and the bomb-disposal team is currently examining the vehicle and making sure there are no more explosive devices," MENA quoted a security source as saying.
The blast came one day after the assassination of Egypt's Prosecutor General Hesham Barakat in a car bombing in Cairo. It also coincides with the second anniversary of the June 30 mass protests that led to the overthrow of former Islamist President Mohamed Morsi in mid-2013.
In response to the top prosecutor's murder, Egyptian President Abdel-Fattah al-Sisi vowed during the man's funeral on Tuesday to amend criminal procedure laws to make faster trials of arrested Islamists and suspected terrorist.
Also on Tuesday, at least three militants were killed and ten others arrested during security raids in Arish and Sheikh Zuweid cities of Egypt's restive North Sinai, security sources in the peninsula told Xinhua.
The extremists are believed to be loyalists of the Sinai-based, al-Qaida-inspired Ansar Bayt al-Maqdis (ABM) militant group, which has changed its name to "Sinai State" and vowed loyalty to the regional Islamic State (IS) militant group.
Terrorist activities have mounted in Egypt since Morsi's ouster in July 2013 and the following security crackdown on his loyalists that left over 1,000 killed and thousands more arrested.
On the other hand, hundreds of police and army personnel have been killed in attacks carried out by extremists and self-proclaimed Islamists since Morsi's removal.
In its annual report released in late May, Egypt's National Council for Human Rights said that the violence since Morsi's removal has resulted in the death of 2,600 people, including 700 police and army men, 550 civilians and 1,250 Brotherhood members and supporters.