Smoke rises behind an Islamic State flag after Iraqi security forces and Shiite fighters took control of Saadiya in Diyala province from Islamist State militants.Reuters

Abu Rumaysah, a 31-year-old Indian-origin ISIS suspect, who is fighting in Syria, has posted a picture of him on Twitter posing with an AK-47 rifle and his new born baby.

Rumaysah, born as Siddhartha Dhar, posted the photo on Twitter on Thursday morning, boasting about the fact that his son will grow up in the Islamic State, reports the Independent.

In September Dhar was arrested in Britain with eight others on suspicion of encouraging terrorism. He however was released on bail and fled soon afterwards.

Dhar took a bus to Paris with his pregnant wife and four young children and travelled to Syria before joining ISIS.

After declaring his arrival in Syria, the wanted terror suspect made yet another announcement on Twitter - the birth of his baby boy.

"He is another great addition to the Islamic State. And he's definitely not British," the Kashmiri Pandit said about the baby.

Dhar was well known for his desire to join ISIS and declared his feelings openly on television shows.

"Hopefully soon we can join forces to crush the global Crusade against Islam and Muslims in the East and West," Dhar wrote.

In an interview on Channel 4 News earlier this year, the ISIS suspect said he would happily denounce his British citizenship so that he could go to Syria and live in what he called "the Islamic State," under "the Shariah."

"I hope that one day Britain gets to live under the Shariah as well," Dhar added.

About 500 British citizens are said to have travelled to Iraq and Syria to join ISIS' battle to establish a hardline caliphate.