The first small group of Iraqi Kurdish fighters crossed the Turkish border Thursday and arrived in the besieged Syrian city of Kobani to help fellow Kurds fight off the militants of the Islamic State, pro-opposition Syrian activists said.
Elsewhere, fighters from the Islamic State stormed an important oil facility in central Syria, various sources reported, and were said to be marching on the Tiyas air base in Homs province.
The Kobani reinforcements, led by a small vanguard of about a dozen troops, are expected to eventually number about 150, providing badly needed assistance to the city's defenders. A separate contingent of fighters from a pro-Western Syrian rebel group arrived Wednesday.
Kobani, just yards from the Turkish frontier, has become an emblem of the West's confrontation with the Islamic State, which has seized control of a large swath of Syria and Iraq. A campaign of U.S.-led airstrikes is attempting to dislodge them from their positions around Kobani and elsewhere.
The British-based Syrian Observatory for Human Rights, which supports the Syrian opposition, said the first 10 Iraqi Kurdish soldiers, or peshmerga, crossed into Syria at noontime. Crowds made up mainly of Kurds braved wind and rain to cheer on the peshmerga as they passed through Turkish territory.
Kobani was the scene of heavy overnight clashes, and the Islamic State fighters have been trying to seize control of the nearest border crossing to Kobani.
The assault on the city has been going on for six weeks. An estimated 800 people have been killed, and tens of thousands of civilians have fled.
The oil and gas facility the Islamic State was said to have stormed -- Jabal Shaaer, about 65 miles east of Homs city -- would add to the group's control of various energy-producing infrastructure. The Syrian Observatory for Human Rights said at least 30 of the field's guards and Syrian soldiers were killed in a blitz attack.
Syrian state media confirmed that three wells had been seized by the group, but put the death toll at seven. Al-Watan, the government's daily newspaper, quoted a military source as saying pro-government forces made a "tactical retreat" to regroup and launch a push to regain control of the facility.
Control of the oil fields has been fiercely contested in recent months. In June, Islamic State fighters had briefly taken over the Jabal Shaaer facility, but were ejected by government forces. The group seemed confident enough of its current push to boast that "lions of the Islamic State" had seized weapons, ammunition and armored vehicles in the attack.
The statement was accompanied by a number of high-resolution images purporting to show the bloodied corpses of regime soldiers as well as the oil facility, which appeared undamaged.
Special correspondents Johnson reported from Mursitpinar and Bulos from Amman, Jordan. Staff writer Laura King in Cairo contributed to this report.