* White House says no justification for targeting camp
* Assad says army will fight for "final victory"
* 30 soldiers killed as militants overrun gas field
* Violence eases in Aleppo after accord comes into effect
By Suleiman Al-Khalidi and Lisa Barrington
AMMAN/BEIRUT, May 5 (Reuters) - Air strikes on a camp housing Syrians uprooted by war killed 28 people near the Turkish border on Thursday, a monitoring group said, and fighting raged in parts of northern Syria despite a temporary deal to cease hostilities in the city of Aleppo.
The Syrian Observatory for Human Rights said the dead included women and children and the death toll from the air strikes, which hit a camp for internally displaced people near the town of Sarmada, was likely to rise.
Footage shared on social media showed rescue workers putting out fires which still burned among charred tent frames, pitched in a muddy field. White smoke billowed from smouldering ashes, and a burned and bloodied torso could be seen in the footage.
"There were two aerial strikes that hit this makeshift camp for refugees who have taken refuge from fighting in southern Aleppo and Palmyra," said Abu Ibrahim al-Sarmadi, an activist from the nearby town of Atmeh who spoke to people near the camp.
Nidal Abdul Qader, an opposition civilian aid official who lives about 1 km (half a mile) from the camp, said around 50 tents and a school had burned down.
The White House said the victims were innocent civilians who had fled their homes to escape violence. "These individuals are in the most desperate situation imaginable, and there is no justification for carrying out military action that's targeting them," spokesman Josh Earnest said.
Sarmada lies about 30 km (20 miles) west of the city of Aleppo, where a cessation of hostilities brokered by Russia and the United States had brought a measure of relief on Thursday. But fighting continued nearby and President Bashar al-Assad said he still sought total victory over rebels.
Syrian state media said the army would abide by a "regime of calm" in Aleppo that came into effect overnight for 48 hours, after two weeks of death and destruction.
The army blamed Islamist insurgents for violating the agreement overnight, saying they had shelled government-held residential areas of divided Aleppo indiscriminately. Residents said the violence eased by morning and more shops opened up.
Heavy fighting was reported in the southern Aleppo countryside near the town of Khan Touman, where al Qaeda's Syrian branch Nusra Front is dug in close to a stronghold of Iranian-backed militias, a rebel source said.
Rebels were attacking government positions around the town and government forces carried out air attacks on the area, pro-Syrian government television channel Al-Mayadeen and the Observatory said.
In the east of the country, Islamic State militants captured the Shaer gas field, their first gain in the Palmyra desert area since they lost the ancient city in March, according to rebel sources and a monitor..
Amaq, an IS-affiliated news agency, said Islamic State militants killed at least 30 Syrian soldiers stationed at Shaer and seized heavy weapons, tanks and missiles.
Assad said he would accept nothing less than an outright victory in the five-year-old conflict against rebels across Syria, state media reported.
In a telegram to Russian President Vladimir Putin thanking Moscow for its military support, Assad said the army was set on "attaining final victory" and "crushing the aggression".
The British-based Observatory and a resident reported rebel shelling of the government-held side of Aleppo, which was Syria's commercial hub and largest city before the war.
But a resident of the rebel-held eastern part of the city said that although warplanes flew overnight, there were none of the intense raids seen during the past 10 days. People in several districts ventured onto the streets.
"From last night it was positive and my wife went out to shop and shops opened and people breathed. We did not hear the shelling and bombing we had gotten accustomed to," Sameh Tutunji, a merchant said.
A rebel source also said that despite intermittent firing across the city's front lines, fighting had subsided and no army shelling of residential areas had been heard.
"Although we're seeing less fighting today, the massive onslaught of violence over these past two weeks would make almost anything look like improvement," the North Syria Director for aid organisation Mercy Corps Xavier Tissier said.
Rebels also said government helicopters dropped barrel bombs on rebel-held Dahyat al-Rashdeen al Junobi, northwest of Aleppo, and near the Jamiyat al Zahraa area, which saw a rebel ground assault pushed back on Wednesday.
The recent surge in bloodshed in Aleppo had wrecked a February cessation of hostilities agreement sponsored by Washington and Moscow, backers of the rival sides. The truce excluded Islamic State and the Nusra Front.
A spokesman for the mainstream opposition said the Saudi-based High Negotiations Committee (HNC) supported the deal but wanted the truce to cover all of Syria, not just Aleppo. It accused the government of violating it.
Syria's foreign ministry blamed Thursday's fighting on the "armed terrorist groups", a reference to the rebels and insurgents, and their foreign backers. "They only want blood and fire for Aleppo without caring if they kill Syrians and destroy their country," it said. (Reporting by Suleiman Al-Khalidi in Amman and Lisa Barrington in Beirut; Editing by Dominic Evans)
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