Friday's attack, in which the driver was also killed and seven others were injured, took place in Cabinda, a province where guerrillas have fought a secession campaign for decades.
"We lost the assistant coach and the press officer," said Messan Attelou, chief spokesman for Togo's football federation.
"We are going now to see and talk to the players and then make a decision whether or not we take part in the competition," he told Reuters at Cabinda airport.
The attack came five months before South Africa hosts the World Cup, the first African nation to hold the world's biggest single sport event.
"We asked that all delegations inform us when they would arrive and provide the passport number of their players," he told the sports weekly A Bola.
"Togo was the only team not to respond and did not inform COCAN it was coming by bus ... The rules are clear: No team should travel by bus. I don't know what led them to do this."
A shaken Togo captain Emmanuel Adebayor, who escaped the attack unharmed, said his team might quit the African Nations Cup, which is due to open on Sunday and feature some of the world's most valuable players.
"We keep repeating (that) - Africa, we have to change our image if we want to be respected - and unfortunately that is not happening," Adebayor told the BBC World Service.
"A lot of players want to leave. They have seen death and want to go back to their families."
Cabinda, the scene of attacks by separatists even after Angola's 27-year civil war ended in 2002, is responsible for half of oil production in Angola, which rivals Nigeria as Africa's biggest producer.
"This is a real blow for Africa. It will obviously be linked directly with the W
