Zambia's new president, Rupiah Banda, promised to fight poverty and reach out to the opposition as he was sworn in on Sunday as the country's fourth head of state, following a hotly fought election.

Zambia's chief justice Ernest Sakala gave Banda the oath of office just two hours after the election commission declared him the winner, in a ceremony outside the national parliament in Lusaka.

South African President Kgalema Motlanthe and Zimbabwe's leader Robert Mugabe attended the ceremony.

After his swearing-in, Banda asked the oppostion to "put aside petty squabbles."

"It is not my intention to govern a divided nation," he said. "This election will not be allowed to divide us."

"My priority will be to fight poverty. Too many Zambians have been left behind," he said.

Banda eeked out a narrow victory over opposition leader Michael Sata of the Patriotic Front, in an election called after the death of president Levy Mwanawasa in August.

Banda had campaigned as a steady hand to guide the country after Mwanawasa's death, and in his speech on Sunday he again promised to maintain the late president's economic policies and fight corruption.

Sata has accused election officials of rigging the vote, and has warned that he would not accept defeat. He has made no public comments since Banda's victory was declared.

Scores of angry Sata supporters rioted in a Lusaka slum after Banda took the lead in the race late on Saturday. Police used tear gas to break up the protest.

AFP