DAR ES SALAAM (Reuters) - Tanzanian opposition lawmaker Tundu Lissu, a fierce critic of President John Magufuli s government, was seriously wounded in a gun attack on Thursday, police and party officials said. Magufuli condemned the shooting and ordered the country s security forces to investigate the incident. Lissu underwent emergency surgery after being shot in the abdomen and other parts of the body by unknown gunmen outside his residence in the administrative capital Dodoma, they said.  Lissu has suffered multiple gunshot wounds and is being treated at the main public hospital in Dodoma,  said Tumaini Makene, spokesman for the main opposition CHADEMA party.  We strongly condemn this attack and are closely monitoring his condition,  the party said in a separate statement. James Kiologwe, a doctor at Dodoma regional hospital, said Lissu was in stable condition. Police said an investigation had been launched into the attack on Lissu, a senior lawyer and CHADEMA s parliamentary chief whip. Police said they did not know what had motivated the attack and the suspects were still at large.  I have been saddened by reports of the shooting of Hon. Tundu Lissu. I pray for his quick recovery,  Magufuli said on Twitter.  Law enforcement agencies should hunt down all those involved in this barbaric act and bring them to justice.  Lissu is a vocal opponent of Magufuli and has been arrested on several occasions and charged with incitement. He was detained most recently in July after having called Magufuli a dictator. He was subsequently released.  The authorities must take steps to reassure Tanzanians and the world that this shooting was not politically motivated,  rights group Amnesty International said in a statement. 