The al-Qaida-linked Ansar al-Shariah released a list of seven names of fighters and residents it said were killed in the "crusader American strike" in the eastern town of Ajdabiya.
A second statement from an umbrella group for militias called the Shura Council of Ajdabiya and its Surroundings also did not include Belmokhtar among the dead.
Neither group directly denied Belmokhtar was killed.
U.S. officials initially said they believed they hit their target, but later said assessments were still underway. A Libyan official said tests were needed to identify the dead, who numbered at least 17.
Believed to be 43 years old, Belmokhtar fought in Afghanistan and was reported to have lost his eye in combat. He was one of a number of Islamist fighters who have battled Algeria's government since the 1990s, later joining al-Qaida in the Islamic Maghreb, the group's North Africa branch.
He was also known as "Belaouer the One-Eyed," ''Abou al-Abbes" and "Mr. Marlboro," because he allegedly smuggled cigarettes through the Sahara and the Sahel region.
He formed his own group and led the January 2013 attack on Algeria's Ain Amenas gas complex that killed at least 35 hostages, including three Americans. He later emerged in Libya, and is believed to have been based in the western and southern parts of the country.
Belmokhtar is accused of masterminding the attack on the gas plant in which two Canadians were involved. The RCMP confirmed that Ali Medlej and Xris Katsiroubas, both of whom went to the same high school in London, Ont., were among the 29 dead terrorists found in the Algerian gas plant.
Belmokhtar, an Algerian national, is also believed to have played a central role in the kidnapping of veteran Canadian diplomat Robert Fowler, who was working in Niger as a United Nations special envoy.
Fowler and his colleague, Louis Guay, were kidnapped in 2008 and held for more than four months before being freed. Published reports have said Belmokhtar was the commander of the terrorist cell that kidnapped Fowler and Guay.
In May 2013, The Associated Press reported that it obtained an al-Qaida letter that suggested about $1 million was paid for the release of Fowler in Niger four years before.
In a book he published, Fowler said he did not know if a ransom was paid.
The U.S. filed terrorism charges against Belmokhtar in connection with the Algeria attack. Officials have said they believe he remained a threat to U.S. and Western interests.
In the airstrikes on Sunday, two F-15 fighter jets launched multiple 500-pound bombs, a U.S. official said. Authorities say no U.S. personnel were on the ground for the assault.
— with files from The Associated Press