A rebel group called Flec-Fac said they had shot at the bus not realising it was the Togo team, and promised no more attacks during the Africa Nations Cup.
Another Flec faction had previously claimed responsibility.
The leaders of both factions, who live in Europe, campaign for independence for the oil-rich province of Cabinda.
They have both been involved in a long-running low-level insurgency in the province.
Angolan officials say they have arrested two people over Friday’s attack but released few details.
Angolan officials now say that the Angolan driver of the bus who was initially reported killed in the attack in fact survived.
Flec, the Forces for the Liberation of the State of Cabinda, began its operations in the 1960s fighting against Portuguese rule, but in recent years has splintered into several rival factions.
In a statement distributed to journalists in Luanda, Flec-Fac said the Angolan armed forces had been the intended target and regretted the deaths of two members of the Togolese party.
The group said it would “abstain from any act of violence in Cabinda during the tournament”.
Flec-Fac spokesman Jean-Claude N’Zita, who lives in exile in Switzerland, told AFP news agency his group were not terrorists.
“Every time the Armed Forces of Cabinda [Flec-Fac] sees an Angolan convoy, they open fire,” he said.
“We have nothing against our African brothers, and we like football.”
The claim of responsibility came days after a leader of Flec-PM said it was his group who carried out the attack, and promised more violence during the Africa Cup of Nations.
Analysts say Flec-Fac has a proven track record of fighting against the Angola government and its claims should be taken more seriously.
Meanwhile South Africa’s World Cup boss Danny Jordaan has questioned how Angola could have allowed the attack to happen.
“How long is it known that there is a separatist group in Angola for many many years? What are the possibilities of a terror attack? It was known,” Mr Jordaan told AFP.
“It is a responsibility of the host nation to deal with those issues.”
Correspondents have already questioned why the Togo team travelled by bus from neighbouring Congo.
Officials travelling to the province almost always use helicopters or planes.
Cabinda is separated from the rest of Angola by a stretch of land belonging to the Democratic Republic of Congo.
It was absorbed into Angola in 1975 when former colonial power Portugal pulled out.
But Cabindans were never consulted and many have never accepted Luanda’s authority over them.
