ERBIL, Kurdistan Region – The Kurdistan Workers’ Party (PKK) appealed to young Kurds in Turkey to rush to the aid of Syrian Kurds in Kobane, where its sister forces have been alone resisting renewed assaults this week by the Islamic State (IS).

Hundreds were reported fleeing the city amid indiscriminate shelling by the IS, as the Islamic rebels turned heavy weapons seized in Iraq on Kobane, in attacks that began Monday.

The People's Protection Units (YPG), a PKK wing, has been fighting against IS and other jihadi groups for the past three years.  Since the outbreak of the Syrian civil war it has been a bulwark against IS and other radical Islamic forces moving into the Kurdish-populated areas (Rovaja).

The YPG reported three heavy rockets fired into Kobane in the latest round of fighting, turning fear among residents into outright panic.

The PKK called on Kurds in Turkey’s Kurdish regions (North Kurdistan) to volunteer to fight for Kobane.

“Young people from the North must go to Kobane and join the historic, honorable resistance," said a statement by the Group of Communities in Kurdistan (KCK), the PKK’s umbrella organization.

"Kobane is also the symbol of the Rojava Revolution, and in reality it is a part of North Kurdistan,” it added.

Kobane is one of three “cantons” where the YPG’s political wing declared unilateral autonomy last year. That remains urecognized, largely because the PKK is labeled a terrorist organization in  Turkey, the European Union and the United States.

The Syrian Kurds have remained isolated in their war with IS, as global efforts galvanize against the jihadis in Iraq. The US has been conducting air strikes against IS positions in Iraq since last month, with France saying Thursday it will also step into the air campaign.

The US congress has authorized arming the Syrian Free Army, but it is unclear whether the Kurdish forces would receive US lethal assistance: Turkey is a staunch opponent of arming any group affiliated with PKK. The guerrilla group is outlawed in Turkey, but has huge support among the country’s 15 million Kurds.

"Join the YPG and become a well trained soldier,” Murat Karayilan, a senior PKK leader, was quoted as saying. He called on Turkey’s young Kurds to “join their brethren in Rojava,” the pro-PKK Firatnews reported.

Karayılan warned of a humanitarian disaster and the threat of massacre by the IS, comparing what could happen in Kobane to the IS assault on Shingal in Iraqi Kurdistan, where hundreds of Yezidi men were murdered and countless women were taken as war prize by IS.

"Action must be taken immediately to prevent such a disaster. Everyone must do what they can," he declared.

Karayilan slammed Turkish silence over events in Rojava, accusing Ankara of tacit support of the jihadis.

According to the pro-PKK Hawarnews, the IS attack has triggered a mass exodus of thousands, including Kurds, Arabs and other minorities, toward the Turkish border. It said a dozen Kobane villages had been deserted.

"We have lost touch with many of the residents living in the villages that ISIS (Islamic State) seized," Ocalan Iso, deputy commander of the YPG in Kobane, told Reuters.

Turkey, which has 49 diplomats held hostage by IS, has come in for criticism for inaction against the group, most fiercely by the Kurdistan Regional Government (KRG) in northern Iraq.

Karayilan said that by closing its border to the Syrian Kurds, Turkey was assisting the IS. He accused Ankara of "complicity" in the siege of Kobane.