BRUSSELS (Reuters) - NATO said on Friday it was checking whether one of its air strikes in Libya mistakenly wounded at least 16 rebels and destroyed six of their combat trucks.

Rebel spokesman Farag al-Moghraby said the incident took place near Ajdabiyah, a town about 180 km (113 miles) south of Benghazi, the base for opposition to long-time Libyan ruler Muammar Gaddafi.

"(It was most likely) a NATO air strike that had mistakenly hit that location," he told Reuters by telephone. "We are investigating where the air strike came from, whether it's NATO or Gaddafi forces."

He said no one was killed in the incident, but six rebel pickup trucks fitted with anti-aircraft guns had been destroyed.

NATO military spokesman Mike Bracken said the alliance was not currently in a position to confirm or deny the report as it did not have personnel on the ground in Libya.

He added: "NATO is aware of the media reports of an incident involving opposition forces. We are checking the details and circumstances of this particular incident."

NATO is under pressure to escalate Libya missions that might turn the fight, especially on the stalemated eastern front, in the rebels' favor.

Bracken said so-called "dynamic targeting" -- when air crews pick targets while in flight -- took longer to investigate than pre-planned bombing sorties.

NATO accidentally struck rebel positions on several occasions early in its three-month-old Libyan air campaign. It said at the time that the similar appearance and equipment of rebel and Gaddafi forces in the desert terrain made targeting difficult.

Western officials have also accused Gaddafi's military of hiding equipment in urban areas or behind human shields.

(Reporting by David Brunnstrom; Editing by Dan Williams and Peter Graff)