A prominent opposition member of parliament in Tanzania has been shot and "seriously wounded" by unknown attackers at his residence in the administrative capital, Dodoma, according to officials.

Tundu Lissu, 49, underwent emergency surgery after being shot in the abdomen on Thursday. James Kiologwe, a doctor at Dodoma Regional Hospital, said he was in stable condition.

"Lissu has suffered multiple gunshot wounds," Tumaini Makene, spokesman for the main opposition CHADEMA party, said shortly after the incident.

"We strongly condemn this attack and are closely monitoring his condition."

Mwigulu Nchemba, Tanzania's home affairs minister, confirmed the incident and Lissu's condition, adding that the government would issue a statement after receiving a medical report.

The motive for the shooting was unclear.

Gilles Muroto, regional police commander, said an investigation was under way.

"We are asking fellow citizens with information to help us," he said, adding that initial enquiries were focusing on a car believed to have followed Lissu to his home.

Fierce critic

Human rights groups condemned the shooting as a "cowardly attack".

"This cowardly attack on one of Tanzania's most fearless and prominent politicians raises concerns about the safety of all dissident voices in the country, at a time when space for dissent is quickly shrinking," said Sarah Jackson of Amnesty International.

"This heinous crime must not be swept under the carpet ... The authorities must take steps to reassure Tanzanians and the world that his shooting was not politically motivated."

Lissu, a fierce critic of President John Magufuli and his government, is the president of the Tanganyika Law Society.

He has previously been arrested by police on several occasions and charged with incitement.

In July, he was arrested and later released after having called Magufuli a "dictator" over alleged attacks on the opposition and the media.