BISSAU (Guinea-Bissau) - ARMED men attacked the residence of Guinea-Bissau's president and engaged security forces in a three-hour gunbattle in the capital of the West African country before dawn on Sunday.

It was not immediately clear if President Joao Bernardo 'Nino' Vieira was in the building at the time of the attack or if he was hurt.

An Associated Press reporter heard heavy artillery and RPG rockets being fired just after midnight on the president's home in Bissau. Dozens of security forces have surrounded the building.

The government has issued no statement, however, and state-run media made no mention of the attack in their Sunday morning bulletins.

In a statement Sunday about Guinea-Bissau, African Union commission chairman Jean Ping said the AU rejects 'any unconstitutional change of government and condemns in advance any attempt to seize power by force.'

The United Nations has said the impoverished nation of 1.5 million on Africa's Atlantic coast is a key transit point for cocaine smuggled from Latin America to Europe.

A week ago, Guinea-Bissau held parliamentary elections amid opposition allegations that some politicians were being funded by drug money. Former President Kumba Yala - whose party lost seven seats in the 100-seat legislature while the governing party went from 45 seats to 67 - accused Vieira of being the country's top drug trafficker. -- AP