German authorities have foiled a plot by militants linked to ISIS to bomb as many 'infidels' as possible.

Police in the country arrested three men in Offenbach, near Frankfurt, on suspicion of planning an attack on behalf of ISIS using explosives, prosecutors said today.

The main suspect is a 24-year-old German of Macedonian origin who had wanted to manufacture explosives and had tried to buy a weapon online, the Frankfurt prosecutors said.

His two accomplices are Turkish nationals aged 22 and 21 and were arrested in a series of raids today.

The three suspects wanted to kill as many 'infidels' as possible in the attack, Frankfurt chief prosecutor Nadja Niesen added in a statement.

German police arrested three men during raids in the city of Offenbach (pictured) who are suspected of plotting an ISIS terror attack

She added: 'The intervention occurred in time to prevent a concrete threat.'

Some 170 police officers searched three apartments in the western city of Offenbach and detained the men, who were already known to authorities.

Niesen said the suspects appeared to have planned an attack in the Rhine-Main region with the intention of killing 'as many people, so-called unbelievers, as possible', but it wasn't yet known whether they had chosen a specific target.

All three suspects are alleged to have spoken of their support for ISIS in the presence of witnesses, who informed authorities, Niesen added.

The main suspect, police also said, had 'explosives-related substances and equipment', following a search of his home.

This week it was revealed that a refugee camp in northern Syria full of ISIS families had turned into a 'mini-caliphate' with the loyal followers of slain leader Abu Bakr Al-Baghdadi still blindly pursuing the group's blood-thirsty aims.

Police in Offenbach (pictured in a file image) detained three men on suspicion of being part of an ISIS terror cell based in the city

More than 70,000 people, mostly women and children, are kept at al Hol in the northeast of the country and thousands of them are suspected ISIS fighters' families.

The Turkish invasion last month depleted the Kurdish guards, leaving the camps vulnerable to stabbings and gun attacks.

Several ISIS fighters previously fled Kurdish controlled prisons in the area and the fear among European nations was that the instability in the region could lead to jihadists flooding out of Syria to launch terror attacks.

Turkish government led by Recep Tayyip Erdogan (pictured in Ankara on Sunday) said it had begun sending foreign ISIS fighters back to their home countries

This week Turkish president Recep Tayyip Erdogan announced Ankara would start sending foreign ISIS fighters back to their home countries following his country's invasion and attacks on the Kurds.

Erdogan, and even President Trump, have frequently criticised Europe for refusing to take back their ISIS fighters voluntarily.

Jordanian intelligence recently foiled a plot by two suspected militants to mount terror attacks against US and Israeli diplomats alongside American troops deployed at a military base in the south of the country, state-owned al Rai newspaper reported today.

It said the suspects had planned to drive vehicles into their targets and attack them with firearms and knives.

The suspects will stand trial in Jordan's state security court, according to local media.