Kurdish peshmerga forces streamed across the Syrian border from Turkey late Friday to bolster defenders in the key border town of Kobane which is under assault by Islamic State group jihadists.
Horns blaring, the trucks carried some 150 Iraqi peshmerga fighters, many of them chanting "Kobane" and waving to jubilant crowds who cheered them across the border where they will join the fight against the jihadists.
The Syrian Observatory for Human Rights monitoring group confirmed the Kurdish fighters had entered the embattled frontier town.
The peshmerga drove out of a heavily guarded Turkish military warehouse and headed for the border to reinforce Syrian Kurds in the battle for Kobane, an AFP correspondent reported.
Pro-Kurdish Firat news agency reported the convoy had crossed the border, 10 kilometres (six miles) south of their start point in the Turkish border town of Suruc.
The peshmerga stood atop their pick-ups, waving to onlookers and brandishing their rifles in the air. Turkish police lined the road holding anti-riot shields.
Observatory chief Rami Abdel Rahman told AFP the 150 peshmerga entered Kobane after crossing the border with their heavy weaponry from Tal al-Shair, west of the town.
The fighters had arrived from northern Iraq in two contingents -- one by air and one by land -- but both appeared to be heading to the border together.
The air contingent arrived early on Wednesday and the land contingent the next day. There had been growing frustration among some Kurds over why the deployment was taking so long.
But earlier Friday there was a hint of movement when two trucks took on fuel from a petrol station in preparation for the trip to the border.
Turkish President Recep Tayyip Erdogan took aim at Western leaders for focusing too much on the battle for Kobane, however.
Speaking to reporters in Paris after meeting French President Francois Hollande, Erdogan asked: "Why are coalition forces continually bombing this town of Kobane?"
"We talk about nothing other than Kobane which is on the Turkish border and where there is no one left any more except 2,000 people fighting."
Ankara's decision to permit heavily armed Iraqi peshmerga forces and opposition rebels to cross its border into Syria has sparked condemnation from Damascus, which denounced it as a "flagrant violation of Syrian sovereignty".
The US-led coalition carrying out air raids against IS in both Syria and Iraq has intensified attacks around Kobane.
The Britain-based Observatory reported fierce fighting in central Kobane on Friday.
"Kurdish fighters were able to advance towards an IS position in the north of the town after an operation that killed dozens of jihadists," it said.
The Observatory said Kurdish People's Protection Units (YPG) made advances into the town's central square.
"The jihadists responded by blowing up a booby-trapped vehicle in the square next to the Kurdish positions."
The Observatory also reported that artillery pieces were destroyed and IS fighters killed as coalition air strikes targeted the north and centre of Kobane.
According to experts and extracts of a UN report published by Britain's Guardian newspaper, IS is now recruiting foreign jihadists on an "unprecedented scale".
The latest US figures show that around 1,000 foreign fighters are flocking to fight in Iraq and Syria every month.
In Iraq, government forces Friday attacked the strategic jihadist-held town of Baiji, which has been out of Baghdad's control for months, regaining control of two areas, army officers said.
Baiji lies on the main highway to Iraq's IS-controlled second city Mosul, and its recapture would also help to further isolate militants in the city of Tikrit, to the south.
Iraq's leading Shiite cleric, Grand Ayatollah Ali al-Sistani, meanwhile, urged those battling IS to protect civilians in Sunni battle zones.
"It is up to you to protect the lives of the innocent citizens and protect their property... whatever confession they may belong to," he said.
Sistani, who is revered by millions, has enormous influence among Iraq's Shiite majority.