(BBC) - The US-led coalition has carried out its most sustained air attacks so far on Islamic State fighters attacking the Turkey-Syria border town of Kobane.
Syrian Kurdish fighters said the strikes were the most effective yet but should have come much earlier.
Correspondents said the surge of IS appeared to have been halted, although fighting around Kobane continues.
At least 12 people were killed in protests by Kurds in Turkey about the lack of Turkish military support.
Kurdish Syrian Party leader Salih Muslim said the situation overnight remained very serious with the Kurdish fighters of the YPG militia under intense pressure.
"There is heavy fighting going on by YPG forces and they're trying to defend the civilians.
"There is a very large operation against them."
At least 400 people have died in three weeks of fighting for Kobane, monitors say, and 160,000 Syrians have fled across the border to Turkey.
The latest media release from the US military confirmed five air strikes around Kobane, saying they were on Monday and Tuesday, but without specifying exactly when.
It said the attacks had destroyed four IS armed vehicles and an "IS unit", and damaged one IS tank and one armoured vehicle.
However, the BBC's Paul Adams, on the Syria-Turkey border, says more air strikes were heard on Tuesday afternoon, bringing the total to eight for the day - by far the most sustained coalition action in the area.
He says that as a result, fighting in the city died down considerably - it was quiet but for occasional crackles of gunfire in the afternoon.
Meysa Abdo, the top female Kurdish commander in Kobane, told the BBC's Newshour programme: "Since last night we've seen the most effective air strikes around Kobane ever, however they are a bit late.
"If the coalition had attacked with such strength and effectiveness beforehand, we wouldn't have seen IS reach the city and destroy so many lives."
She said there had been some coordination with the coalition on targeting but that it needed to be more robust. She added: "With the help of coalition air strikes we can defeat IS."
Referring to President Recep Tayyip Erdogan's speech earlier on Tuesday in which he said Kobane was "about to fall", Ms Abdo said: "He is dreaming and Kobane will never fall."
She said there had been fierce fighting: "IS is trying to enter the city but our fighters have shown extreme bravery and resisted their attacks with heavy weapons."
In his speech on a visit to a refugee camp for Syrians, Mr Erdogan said air power alone could not defeat IS: "We had warned the West. We wanted three things: no-fly zone, a secure zone parallel to that, and the training of moderate Syrian rebels."
He said that "the terror will not be over... unless we co-operate for a ground operation", although he gave no further details.
Across Turkey on Tuesday, Kurds vented their anger at the government's lack of military support for the defenders of Kobane.
Police used tear gas and water cannon as unrest spread to at least six cities.
One protester was killed in the south-eastern province of Mus. Most of the other deaths were in Diyarbakir, Turkey's largest Kurdish city.
Dozens of Kurdish demonstrators also smashed a glass door and entered the European Parliament in Brussels.
Hundreds more protesters demonstrated in Berlin and other German cities.
In New York, the UN's special envoy for Syria, Staffan de Mistura, said the Syrian Kurds had defended Kobane with great courage and the international community should now take concrete action to support them, although he did not say whether he thought ground troops should join the fight.
