The US bombing strikes on ISIS camps in Libya that killed dozens of fighters cost almost $9million.

US B-2 bombers carried out air strikes against Islamic State camps outside of Sirte, Libya, on Wednesday night, killing dozens of militants, US defense officials said on Thursday.

Two US defense officials, speaking on the condition of anonymity, said the strikes were carried out 28 miles southwest of Sirte against two camps and done in cooperation with Libya's UN-backed Government of National Accord.

They said there were no women or children in the camps.

US B-2 bombers (like the one seen in the above stock image) carried out air strikes against Islamic State camps outside of Sirte, Libya, on Wednesday night, killing dozens of militants, according to defense officials

Since the bombing, it has been revealed it cost a total of $8.8 million to have the two jets deliver the deadly payload, according to Yahoo News.

The website says the planes flew for 34 hours each as part of the mission, with a price-tag of $130,000 per hour.

The overall figure is also likely to be significantly higher, due to the roughly 15 aerial refueling aircraft involved in the mission, as well as the bombs that were dropped.

It comes after one of the officials said initial reports showed dozens of militants were killed in the strikes with more than 100 precision guided munitions dropped.

Pentagon spokesman Peter Cook, in a statement on Thursday, confirmed the US military conducted successful strikes.

'The ISIL terrorists targeted included individuals who fled to the remote desert camps from Sirte in order to reorganize, and they posed a security threat to Libya, the region, and US national interests,' Cook said, using an acronym for Islamic State.

Two US defense officials, speaking on the condition of anonymity, said the strikes were carried out 28 miles southwest of Sirte (seen on a map above) against two camps

Libyan forces backed by US air strikes finished clearing the last Islamic State holdout in Sirte last month after a battle of nearly seven months for the militant group's former North African stronghold.

The United States carried out about 470 air strikes against Islamic State targets in Sirte during that campaign.

The loss of Sirte was a major blow for Islamic State, leaving the group without any territory in Libya, although it retains an active presence in parts of the vast country.

One of the officials said initial reports showed dozens of militants were killed in the strikes with more than 100 precision guided munitions dropped. Libyan fighters (above) are seen shooting at Islamic State gunmen in Misrata on March 15, 2015

The jihadist group took over Sirte in early 2015, turning it into its most important base outside the Middle East and attracting large numbers of foreign fighters into the city.

It imposed its ultra-hardline rule on residents, and extended its control along about 155 miles of Libya's Mediterranean coastline.