Sanaa, Yemen (CNN) -- At least 10 people were killed Tuesday on the outskirts of Yemen's capital as government forces bombarded residential areas, witnesses said, in the latest example of what a U.N. report calls a "deteriorating humanitarian situation" in the country.
Six of the dead were children or women, according to residents of the Arhab district.
At least 17 other residents were wounded, two of them critically, the witnesses said.
The government said it was seeking to subdue tribal fighters.
"Armed tribes are attacking military posts and the government only attacks those who are armed and are seeking to enter its bases," said government spokesman Abdu Ganadi. "The tribal fighters are supported by the opposition parties and those military leaders who defected from the Yemeni army."
However, witnesses said that civilians, not tribal fighters, made up the bulk of Tuesday's fatalities.
"The government is killing innocent civilians and then claims they were criminals," said Abdullah Haneq, a witness in Arhab. "Tribes are not fighting the government, they are defending themselves from the attacks of the regime."
He said that the attacks on the district had not stopped for two days.
Six residents told CNN that the air attacks took place in residential areas, far from any military contingent or camp.
Hundreds of tribal fighters have been clashing with government forces since June, when tribes in Arhab announced their loyalty to the Yemeni revolution. During the past month, fighters have seized control of military posts and camps in the district.
Tribal fighters said Tuesday that they damaged three tanks and six armored vehicles during the prior 12 hours.
The ruling General People Congress website reported that the government attacks focused on the villages of Labwa and Shiraa in Arhab, where fighters sought to attack governmental posts.
Witnesses said that Republican Guards sent more than 30 tanks and armored vehicles to reinforce their troops there.
At least 25 air attacks were reported in Arhab on Tuesday morning.
The attacks coincided with the publication Tuesday of a report by a U.N. human rights assessment mission to Yemen, which calls for immediate action to protect civilians, respect their rights to demonstrate peacefully and deal with the country's "deteriorating humanitarian situation."
The report also calls for "international, independent and impartial investigations" into allegations of human rights abuses related to the protest movement.
The 18-page report was written after a delegation from the Office of the High Commissioner for Human Rights visited Aden, Sanaa and Taizz for nine days in June and July.
"The mission observed an overall situation where many Yemenis peacefully calling for greater freedoms, an end to corruption and respect for rule of law were met with excessive and disproportionate use of lethal force by the state," the report says. "Hundreds have been killed and thousands have suffered injuries including loss of limbs."
The team reports seeing tanks deployed in the southwestern city of Taizz and shelling of the city at night.
"The mission noted that the Yemeni government had lost effective control of parts of the country and within the major cities, where armed opponents appeared to have de facto control," the report says. "The mission also observed that those seeking to achieve or retain power have deliberately sought to punish and cause severe hardship to the civilian population by cutting off vital access to basic services such as electricity, fuel and water."
Despite suffering casualties, protesters "have sought to maintain their peaceful character," it says.
In major cities, it says, several struggles are taking place: Some demonstrators are calling for peaceful change even as armed opponents of President Ali Abdullah Saleh are involved in a violent struggle for power with his supporters.
It adds that the government and its armed opponents have blamed each other for the suffering and hardship. "All sides may be guilty of using and abusing peaceful protesters and the civilian population in this increasingly violent power struggle," it says.
The report further cites allegations of human rights violations committed by government security forces, including the torture and killing of children and other civilians.
Children have also been recruited into the military, says the report, which calls for the release of all prisoners taken into custody at peaceful demonstration.