A Kurdish man carries his son during a rainy day at the Rojova Camp, in Suruc, a rural district of Turkey's Sanliurfa Province, on Thursday. Heavily armed Kurdish peshmerga fighters were traveling by land and by air to join militias defending the Syrian border town of Kobane, also known as Ain al-Arab, from the Islamic State group after setting off from Iraq. Photo: AFP

A small delegation of Iraqi Kurdish fighters crossed the Turkish border into the Syrian town of Kobane on Thursday to prepare the way for dozens more to reinforce the town's defenders, a monitor said.

"Ten peshmerga [fighters] entered Kobane to coordinate the arrival of their comrades, who are still waiting with their weapons in Turkey," said the Syrian Observatory for Human Rights.

Turkey's pro-Kurdish Firat news agency also reported that a delegation of 10 peshmerga had entered Kobane for talks with the Syrian Kurdish People's Protection Units (YPG) militia defending the town.

About 150 peshmerga are expected to join Syrian Kurds and Arab rebels fighting Islamic State (IS) jihadists in Kobane, after Turkey agreed to their passage last week.

Two groups of peshmerga linked up on the Turkish border on Thursday, as a convoy carrying heavy weapons joined a second group of fighters who had arrived by air the day before.

The Observatory reported that IS was pounding northern areas of Kobane along the border with mortars and heavy artillery.

IS fighters had also launched an assault on a northern neighborhood overnight but were pushed back by forces from the YPG, said the Britain-based group, which relies on a broad network of activists for its reporting.

Also on Thursday, Syria accused Turkey of a "flagrant violation" of its sovereignty, as Ankara allowed Iraqi Kurdish peshmerga fighters and opposition rebels to cross its border to battle jihadists.

"Once again, Turkey has shown its conspiratorial role ... by allowing foreign forces and terrorist groups to enter Syria," said a foreign ministry statement reported by state television.

"This constitutes a flagrant violation of Syrian sovereignty."

"Syria denounces and rejects this disgraceful behavior by the Turkish government and by its accomplices, who have been responsible for the Syrian crisis from the beginning," said the statement, referring to US pressure to allow the peshmerga and rebels access.

The regime of President Bashar al-Assad has systematically blamed Ankara - a former ally - as well as Washington and Gulf countries for the war that has ravaged Syria for more than three years.

The conflict began as a peaceful revolt demanding political change, but later morphed into a brutal civil war after Damascus unleashed a countrywide crackdown against dissent.