Turkey now looks as if it may launch military operations in Syria and Iraq against Islamic State militants threatening its borders, after a government proposal was sent to parliament on Tuesday that would allow action to "defeat attacks directed towards our country from all terrorist groups" in the two countries.

The move comes as IS continues to press a concerted offensive on the majority Kurdish Syrian border town of Kobane, which has taken it to within sight of the Turkish perimeter. Fighting has been heavy and stray shells and bullets have spilled over into Turkey, prompting authorities to deploy tanks and other armed vehicles to the region.

Its an escalation by Ankara, which had refused a major role in a broad US-led anti-IS coalition. This is seemingly because the jihadists held a large number of Turkish hostages — including diplomats and children — which they captured in Iraq's second city of Mosul during in a shock June offensive. However the hostages are now free and President Recep Tayyip Erdogan said during a World Economic Forum meeting in Istanbul on Sunday that Turkey's position had hardened to the point that it "cannot stay out of this campaign."

But Kurds in and around Kobane still see Turkey and IS not as enemies, but collaborators. At a border crossing near the besieged city, where many Syrian Kurds who initially fled IS are gathering to return to their hometown to help defend it, it was regarded as common knowledge that Turkey was arming IS.

"They have heavy weapons and support from the Turkish government, everyone knows this," one 23-year-old man, who gave his name as Ahmed Kobane, told VICE News. The city's defence minister ?smet Sekh Hesen said in a phone conversation from the center of the city that he too believed Turkey was supporting his opponents.

The belief in Turkish collusion with IS has helped fuel a series of nearby clashes between Turkish Kurds and local security forces which saw heavy use of tear gas by riot police and left a number of protesters injured. Some there said that they were demonstrating against the government and leveled allegation after allegation about its relationship with IS.

Mehmet Karaylan, the provincial Co-chairman for Gazientep with the pro-minority rights Peoples' Democratic Party (HDP), who was protesting there last week, told VICE News during a break in clashes that he had talked to a number of people who had seen tanks being delivered by train to IS, voicing one of the most widely circulated rumors.

"IS [is] saying that they made an agreement with the Turkish government to get them," he said, adding that in his view even negotiating with IS for hostages was tantamount to recognizing the group's self-proclaimed caliphate.

Karaylan went on to say that if the Turkish government did not help Kobane, it would be obvious where their allegiances lay.

"They have to do something gravely about Kobane and support its resident to keep the city," he said. "If they will are silent about this situation, everyone will understand that the Turkish government is supporting IS."

Nearby, Serhat Ovulu, a 34-year-old Turk also from Gaziantep and affiliated with the Kurdish Democratic Regions Party (BDP) alleged that other weapons had been supplied to IS, and that two floors of Gazientep Medical Park were being dedicated to treating ISIS fighters.

"The Turkish state is a terrorist state... They sent a train to IS with weapons, but we saw it," he said. "At Akcakale gate they support IS," he added, referring to a town and border crossing around 40 miles east and directly north of IS's Syrian stronghold of Raqaa. Border guards there later told VICE News that only Syrians were allowed to pass into Syria and the border was closed entirely from the other direction.

There are perhaps reasons why Turkey might previously have wished at least not to hinder some of IS's activities. The country does not like the idea of a powerful Kurdish presence on its doorstep, especially one that, like the YPG in control of Kobane, has links to the Kurdistan Workers' Party (PKK), which has fought for more than 30 years for greater autonomy within Turkey and as a result is considered by authorities to be a terrorist group.

Turkey has also been a longstanding backer of Syrian rebel groups, some of which are also hardline Islamists. When IS initially appeared in Syria it too appeared to be concentrating on bringing down President Bashar al-Assad's government, although it later veered off into capturing its own territory and implementing its extreme interpretation of Islamic law. Even now though, Ankara is likely concerned that weakening it could strengthen Assad.

However, some of the allegations don't stand up to even cursory scrutiny, analysts say. The supposed delivery of tanks, which is repeated as fact by Karaylan and by many other local Kurds, as well as reported by some parts of the local media, is particularly striking.

Most sources of the rumors lead back to content such as this piece on CNN's user generated iReport platform which claims Turkey gave the Islamic State 49 "war tanks" along with weapons in exchange for the release of the Mosul hostages.

The short article is accompanied by grainy footage of trains carrying armored vehicles, but not stopping or delivering them, and claiming to show the tanks in question. iReport is far from reliable, however, and is not "edited, fact-checked or screened" by CNN itself, as a disclaimer points out. It has a dubious track record too, having been used to distribute other demonstrably false content, such as claims that Turkish police for some reason used Vietnam War-era herbicide Agent Orange on protesters during the Gezi Park demonstrations. The canisters were in fact orange smoke.

Pieter Wezeman, Senior Researcher at the SIPRI Arms and Military Expenditure Program, told VICE News that the idea of Turkey supplying arms, especially heavy weapons to IS seemed "outlandish."

It would also be easy to detect, for a start. Turkey is very dependent on some the main players in the anti-IS coalition — including the US, France and Germany — for its military equipment. The country operates mainly German and American tanks of a type which IS would not otherwise (i.e. by looting from the Iraqi and Syrian armed forces) have access to. The first sighting of such a vehicle in an IS video would be pounced on by an army of Syria-watchers and Turkey, as the only suspect, would be left to deal with some severely pissed off suppliers.

To make the story seem even less plausible, the "tanks" actually appear to be mobile artillery pieces (possibly the M-109, M-52T or the T-155 Firtina), which Wezeman sees as even easier to trace back to Ankara.

"Turkey supplying those to ISIS would be really unlikely... I am sure these weapons have never been delivered to Syria and would very likely be linked to the Turks as soon as they would turn up in ISIS hands," he said.

The end result from either scenario would likely ruin both Turkey's Western military imports as well as its Gulf-focused weapons exports. Any indication that Turkey had supplied IS with any kind of ordnance could sour Turkish relations with anti-IS coalition members Saudi Arabia and the UAE, and ruin its chances of grabbing a piece of the lucrative arms markets there.

That is not to say that IS has not benefitted from Turkey in some way or another. IS has been able to bring weapons and fighters into its territory through Turkey and smuggle oil out. And it is unlikely that this could have been achieved without contact between border guards and IS militants.

Chatham House Associated Fellow Valerie Marcel told VICE News. "When you look at the volumes [of weapons, people and oil] that are transiting going into Turkey, it's inevitable that there is some collusion from customs and military, and my impression is that its individuals benefiting or profiting, and a sort of passive attitude from the institutions that lets it happen," she said. "This is not an official policy of permitting contraband and smuggling, but it's more than just oil — it's people and weapons and equipment — and I just don't think that it can be happening on that scale without someone turning a blind eye."

Turkey has been tightening its borders recently and cracking down on smugglers, and she expects this process to continue.

"It sounds like the political statements from Turkey indicate that it is that going to take a much more active role, and now we're waiting for a demonstration of that," she said. "But because the hostage situation is now resolved, Turkey is a little bolder now, and I suspect that it is going to hit a little harder at the checkpoints. I don't know how far they will, or can, go, but I expect them to step up their seizures."

Turkey is also expected to play a more active role in the anti-IS coalition too, but to what extent is unclear. And exactly whether this will go any way towards convincing Turkish and Syrian Kurds that it is not backing IS seems even less so.