"Security forces killed six of the remaining attackers," Citizen TV said without giving details or the source.
The Kenya Defence Forces said Monday that three terrorists were killed and a few were injured.
The government said earlier that there were 10 to 15 gunmen fighting inside the upscale Westgate shopping mall where 62 people were killed and 175 were injured, the deadliest attack since the bombing of the US embassy in Nairobi in 1998 that killed more than 200 people.
Somali militant group Al-Shabaab has claimed responsibility for the Nairobi attack, saying it was part of retaliation for the cross-border incursion by Kenyan soldiers in October 2011.
Fresh gunshots where heard around 9:30 a.m. Tuesday, according to people working near the mall and a police officer involved in the operation. When gunfire erupted around 6:20 a.m. at the shopping mall, Xinhua reporters counted about 30 shots.
The fresh fight between Kenyan security forces and gunmen broke the silence that persisted for hours over the night, sparking speculation that the siege of the mall might have ended.
"Our security forces were still combing the huge Westgate shopping centre floor-by-floor to ensure that there were no grenades or any other explosive materials left behind by the terrorists," a senior police officer, who was involved in the operation, told Xinhua over telephone after the gunfight.
The officer, who insisted on anonymity, said there were still gunmen inside the mall and there was exchange of fire between them and security forces.
The special security forces will continue to secure the Westgate mall building for some time to ensure that all bodies were pulled out, the officer told Xinhua earlier Tuesday.
"The building may still be inaccessible to the public and media for a while since there are some bodies yet to be pulled out of the building," the officer said.
"We also want to be sure that there are no dangerous devices left behind by the six terrorists who were killed during the rescue operation," he added.
Kenyan President Uhuru Kenyatta is due to address the nation Tuesday.
Among the dead in the mall attack were visitors from Canada, France, Britain, South Africa, China, India, the Netherlands and the US.
In New Delhi, officials named two of the Indians killed as Sridhar Natarajan, 40, from Tamil Nadu who was an employee of a local pharmaceutical firm Harley's Limited; and Paramshu Jain, eight, the son of Manoj Jain, the branch manager of Industrial Area Branch, Bank of Baroda (Kenya Limited).
Meanwhile, Kenya has beefed up security along its borders with Ethiopia and Somalia to prevent insurgents from entering the country.
Joseph Ole Lenku, Kenya’s cabinet secretary in charge of internal security, said Monday that the security apparatus in the country has been ordered to ensure that no one gets in or out of the country.
All major hotels, restaurants, bars and public service vehicle operators across the country have been directed to review and enhance security arrangements, which include screening visitors.
The Kenyan government said Monday that it was holding "some individuals" for questioning at Kenya's major airport.
Interior Ministry principal secretary Mutue Iringo said the individuals whose identities were not disclosed were arrested at Jomo Kenyatta International Airport en route to Turkey.
"We ask all officers dealing with vital identification documents to be very careful," Iringo said after the arrests.