Kurdish forces defending a Syrian town near the Turkish border clashed with the Islamic State group on Monday after repelling a wide-ranging militant assault the day before in battles that left dozens dead on both sides.

While the Kurds remain in control of the town of Kobani, an Associated Press journalist on the Turkish side of the border saw two black banners with Arabic writing -- one raised over a building and another from a nearby hill -- at the eastern entrance on Monday, suggesting that Islamic State fighters may have regrouped and broken through the Kurdish perimeter.

The Britain-based Syrian Observatory for Human Rights and a statement from the Kurdish force known as the People's Protection Units, or YPG, said more than 45 fighters on both sides were killed Sunday near Kobani, including a Kurdish female fighter who blew herself up, killing several jihadists.

Kobani, known in Arabic as Ayn Arab, and surrounding areas have been under attack since mid-September, with Islamic State militants capturing dozens of nearby Kurdish villages. The assault has forced some 160,000 Syrians to flee and strained Kurdish forces, who have struggled to push back the extremists despite being aided by U.S.-led coalition airstrikes.

On the Turkish side of the border, at least 14 Turkish army tanks took up defensive positions on a hilltop near Kobani. Heavy bombardment could be heard down below as plumes of smoke rose from the town.

A shell from the fighting struck a house and a small grocery store across the border in Turkey, but no one was wounded. At least four people were injured in a similar incident on Sunday.

The YPG said in a statement that there were 50 points of clashes around Kobani on Sunday, adding that 74 Islamic State fighters as well as 15 Kurdish gunmen were killed. The Observatory, which gathers information from activists inside Syria, said 27 jihadists and 19 Kurds were killed in the battles, making it one of the deadliest days since the latest round of fighting began three weeks ago.

Syrian Kurdish forces have long been among the most effective adversaries of the Islamic State group, keeping it out of their enclave in northeastern Syria even as the extremists routed the armed forces of both Syria and neighboring Iraq in recent months.

But in recent weeks the overstretched Kurds have struggled to counter the increasingly well-armed militants.

"They are using tanks, artillery and all kinds of weapons they captured in Iraq and Syria," said Nasser Haj Mansour, a defense official in Syria's Kurdish region, referring to the Islamic State group, which has declared a caliphate in the huge swath of territory it controls in both countries.

Observatory director Rami Abdurrahman said Monday that one of the attacks against Islamic State group the day earlier was carried out by a female Kurdish fighter who blew herself up, killing 10 militants.

The YPG statement identified the suicide attacker as Deilar Kanj Khamis, better known by her military name, Arin Mirkan.

Khamis was a member of a YPG branch known as the Women's Protection Units, or YPJ. The force has more than 10,000 female fighters who have played a major role in the battles against the Islamic State group, Haj Mansour said.

Haj Mansour said Kurdish fighters withdrew from a position on the strategic hill of Mashta Nour near Kobani. Khamis stayed behind, and as the Islamic State fighters moved in she attacked them with gunfire and grenades, eventually blowing herself up. The Kurds then recaptured the position.

"If necessary, all our female and male fighters will become Arin. The attacks by mercenaries of Daesh against Kobani will not be allowed to achieve their goals," the YPG statement said, using the Arabic acronym for the Islamic State group.

Nawaf Khalil, a spokesman for Syria's Kurdish Democratic Union Party, or PYD, said: "Yesterday was a very violent day but they were neither able to enter Kobani nor Mashta Nour."

Khalil added that PYD chief Saleh Muslim Mohammed visited Turkey over the weekend where he met Turkish officials, without providing further details.

Turkish Deputy Prime Minister Bulent Arinc confirmed that Mohammed visited the Turkish capital Ankara, without elaborating.

Arinc said on Friday that Mohammed's group made mistakes in the past by siding with Syrian President Bashar Assad and by creating Kurdish cantons in Syria's north.

"They tried to become a state. They had Assad behind them," Arinc said. "What's happening now? 200,000 people have come to Turkey. (And they are saying)'Oh my God, come and save me."

The PYD denies links to Assad's government, which withdrew troops from the area in 2012, allowing Kurdish forces to assume control and eventually declare their own civil administration.

NATO member Turkey is wary of the PYD, believing it is affiliated with the Kurdish PKK movement, which waged a long and bloody insurgency in southeast Turkey.