Baghdad, Iraq (CNN) -- The U.S. military launched airstrikes targeting ISIS fighters around a key dam in western Iraq on Sunday, the Pentagon said.

It carried out the airstrikes near Haditha Dam at Iraq's request, according to Rear Adm. John Kirby, the Pentagon press secretary.

Anbar Province Deputy Governor Faleh al-Issawi told CNN that Iraqi forces launched a ground offensive with the protection of U.S. air cover and strikes. The aim of the offensive, he said, was to retake the area around the district of Barawana, which is about 6 miles west of Haditha.

The city of Haditha and its dam have remained under the control of Iraqi security forces and Sunni Arab tribes despite ISIS' numerous attempts to seize them.

If the terror group seizes the dam -- the second-largest in the country -- it could prove catastrophic. It provides water to millions of people in western and southern Iraq.

Al-Issawi said the area was being used by militants to launch mortar and other attacks on Haditha and the dam and officials have been concerned that these attacks could hit the dam and cause flooding that would impact the entire province.

The United States also fears the militants could use the water to flood villages and seize control of the nation's lucrative electricity industry.

"We conducted these strikes to prevent terrorists from further threatening the security of the dam, which remains under control of Iraqi security forces -- with support from Sunni tribes," Kirby said.

Fighter and bomber aircraft carried out four airstrikes that destroyed ISIS positions and equipment, including Humvees, a checkpoint and a bunker, U.S. officials said.

Dams as war weapons

ISIS fighters have sought to turn Iraq's dams into weapons.

The group, whose acronym stands for Islamic State in Iraq and Syria, now refers to itself as the Islamic State.

Earlier this year, ISIS fighters opened the gates of Falluja Dam in an effort to stop an Iraqi military advance. Water from the dam flooded various villages.

U.S. forces have kept an eye on Haditha Dam on the Euphrates River, where Iraqi troops held off an ISIS assault last month. The Pentagon said operations will continue to ensure Iraqi forces maintain control of the dam.

"Potential loss of control of the dam or a catastrophic failure of the dam -- and the flooding that might result -- would have threatened U.S. personnel and facilities in and around Baghdad," Kirby said in a statement.

Recapture of largest dam

Last month, U.S. airstrikes helped Kurdish and Iraqi forces recapture Mosul Dam from ISIS.

A breach of that dam, the largest in Iraq, would have endangered Iraqis who live downstream and the U.S. Embassy compound in Baghdad, U.S. President Barack Obama said at the time.

If it gave way, it would send walls of water racing down the Tigris River toward Mosul and its 1.7 million inhabitants. Massive flooding would affect major cities farther downstream, including Baghdad.

Mosul Dam had been the center of an intense battle between the ISIS extremists and Kurdish forces. The U.S. military used air support to help Kurdish forces, including fighters, bombers and unmanned aircraft.

ISIS militants have killed thousands of Syrians and Iraqis as the Sunni extremist group seeks to build an Islamic caliphate stretching across a swath of territory.

The militants have executed two American journalists in recent weeks, slayings analysts describe as a propaganda tool.

CNN's Jomana Karadsheh reported from Baghdad, and Faith Karimi reported and wrote from Atlanta. CNN's Jethro Mullen, Joe Sutton and Tom Dunlavey contributed to this report .