A senior ISIS figher was killed in a helicopter raid in Iraq on Monday, according to the Kurdish regional security council.

The joint attack was carried out by US forces alongside Kurdish counter-terrorism forces to the south of the city of Mosul in northern Iraq. A statement identified one of the dead as Suleiman Abd Shabib al-Jabouri, also known as Abu Saif.

Al-Jabouri was killed with two of his assistants, said the statement.

He is said to be part of the jihadist group's war council and as such a senior member. It seems the attack was a deliberate targeted at Al-Jabouri.

A separate operation earlier on Monday saw the US-led coalition land a helicopter north of Mosul. Witnesses and Kurdish security sources said the troops captured at least one ISIS member from a vehicle.

The US coalition refused to confirm or deny either of the reports.

They come after an offensive to re-take Mosul was put on hold until more forces arrive. The operation was launched last month and consists of Iraqi army troops, US forces and the Kurdish counter-terrorism forces.

Iraq's second largest city is seen as a crucial target in the fight against ISIS in Syria and Iraq. The area fell to the militants between 4-10 June 2014.

Last month one US general told reporters more US troops would be expected in Iraq to carry out the attacks alongside local forces.

Monday's attacks came as US analysts said the terror group had experienced a dramatic drop income after air strikes targeted surrounding oil fields.

Additional reporting by Reuters.