The US government continued its campaign against the Islamic State militants in Syria. The US-led airstrikes targeted a dozen oil refineries overnight and slayed at least 14 ISIS fighters.

The crusade continued a day after the US and five Arab allies opened their military maneuver against ISIS insurgents in Syria with over 200 assaults on some two dozen targets. The US military confirmed that a total of thirteen airstrikes had targeted a dozen small modular oil refineries, which were used by the Islamic State group to sponsor its operations, fund its attacks and fuel its vehicles.

The US airstrikes that targeted oil refineries in Syria were believed to have killed up to five British jihadists, including a teenager from Brighton. Five civilians were also reportedly killed in the assaults carried out by the US, Saudi and United Arab Emirates warplanes as per the Syrian Observatory for Human Rights report.

On Wednesday, the US alongside allied Arab warplanes blasted a dozen oil refineries in Eastern Syria, made the foremost impetus to block off funding for Islamic State. US Defense officials said that the facilities that produce between 300 to 500 barrels of refined petroleum were part of a $2 million (£1.2 million) per day profits stream for the Sunni Muslim extremist group.

The US military said that the US airstrikes hit oil refineries around Al Mayadin, Al Hasakah, near Dayr az Zawr and Albu Kamal were successful. The Pentagon reported that the bombarding of the installations were the latest round of air assaults in Syria.

The US military's Central Command said through a statement that Washington extended its anti-Islamic State air campaign from Iraq into Syria this week, and Wednesday's airstrikes concentrated on 12 targets in the east where the ISIS group governs "small-scale" refineries. Pentagon officials had originally said oil fields were targeted but later pull out that account, saying that refineries had been blown-up.

The well-financed ISIS extremists have apprehended several oil fields in Syria and undeveloped refineries, aiding them to sell trafficked crude oil at economical prices through intercessors in Turkey, Iraq, Iran and Jordan. Experts say the group operates in a Mafia-like manner and in addition to oil smuggling, uses kidnapping payoffs, extortion and robbery for its subsidy.

After ISIS militants held large swathes of Syrian and Iraqi territories, the US launched airstrikes campaign against the group in Iraq last month and stretched the assaults into Syria early Tuesday, with five Arab countries particulary Bahrain, Jordan, Qatar, Saudi Arabia and the United Arab Emirates, joining a alliance effort.

US military officers say warplanes from a number of the countries have dropped bombs on ISIS positions in Syria. Authorities also revealed that a Jordanian aircraft conducted an airstrike overnight in Syria. According to the US Central Command, the latest Wednesday's airstrikes convoluted a mix of fighter jets and unmanned robotic drones.

Also on Wednesday, National security adviser Susan Rice voiced to NBC News that the White House had seen social media news that the allied airstrikes had killed the leader of the Khorasan terrorist organization, Muhsin al-Fadhli. But an anonymous military official said that the Pentagon could not confirm whether al-Fadhli had been killed.

The latest US airstrikes in Syria that targeted oil refineries may have dented the Islamic State groups. But retributions and reprisals are dreaded to occur after the blasting assaults on the terrorist-controlled areas.