Some of the attackers stole weapons from an arms depot at the residence, including rocket launchers, officials said.
The violence followed the announcement on Friday that Guinea-Bissau’s dominant African Party for the Independence of Guinea and Cape Verde (PAIGC) had won a clear parliamentary majority in elections.
The African Union expressed its concern over the fighting, just a week after the country’s parliamentary poll.
Abdoulaye Wade, Senegal’s president, said he had received an overnight telephone call from Vieira.
“He told me that the soldiers were firing at his house,” Wade told Radio France International.
Wade said he sent Senegalese troops to the border with Guinea-Bissau and had prepared an aeroplane to evacuate Vieira and his family, but Vieira had not wanted to leave.
Guinea-Bissau has seen a number of bloody coups and uprisings, and in recent years has become a hub for illegal drugs.