Both sides in Syria's bloody civil war said Saturday that a rural village fell victim to a poison gas attack, an assault that reportedly injured scores of people amid an ongoing international effort to rid the country of chemical weapons.

What exactly happened Friday in Kfar Zeita, a rebel-held village in Hama province some 200 kilometers north of Damascus, remains unclear and likely won't be known for some time. It took United Nations weapons inspectors months to say it was likely some chemical weapons attacks happened last year, including an August attack that killed hundreds and nearly sparked Western airstrikes against President Bashar Assad's forces.

But online videos posted by rebel activists from Kfar Zeita echoed earlier images that sparked a world outcry, showing pale-faced men, women and children gasping for breath at a field hospital. They suggest an affliction by some kind of poison _ and yet another clouded incident where both sides blame each other in a conflict that activists say has killed more than 150,000 people with no end in sight.

The main Western-backed opposition group, the Syrian National Coalition, said the poison gas attack hurt dozens of people, though it did not identify the gas used.

The Britain-based Syrian Observatory for Human Rights, an activist group that relies on a network of on-the-ground volunteers, said the gas attack happened during air raids that left heavy smoke over the area. It reported that people suffered from suffocation and breathing problems after the attack, but gave no further details.

State-run Syrian television blamed members of the al-Qaida-linked Nusra Front rebel group for the attack, saying they used chlorine gas to kill two people and injure more than 100. It did not say how it confirmed chlorine was used.

Chlorine, one of the most commonly manufactured chemicals in the U.S., is used to purify drinking water. But as a gas, it can be deadly, with the German army using it in warfare in World War I. The Geneva Protocol of 1925, which Syria signed, banned its use in battle.

The TV report also claimed the Nusra Front is preparing for another chemical attack against the Wadi Deif area in the northern province of Idlib, as well as another area in Hama. The government station did not explain how it knew the Nusra Front's plans.

Activists in the village could not be reached Saturday.

An activist from Hama who is currently in Turkey and is in contact with residents told The Associated Press that the attack occurred around sunset Friday. The man, who goes with the name Amir al-Basha, said the air raids on the rebel-held village came as nearby areas including Morek and Khan Sheikhoun have witnessed intense clashes between troops and opposition fighters.

An amateur video posted online by opposition activists showed a hospital room in Kfar Zeita that was packed with men and children, some of whom breathing through oxygen masks. On one bed, the video showed six children, some appearing to have difficulty breathing while others cried.

The video appeared genuine and corresponded to other AP reporting of the attack.

Chemical weapons have been used before in Syria's 3-year-old conflict. In August, a chemical attack near the capital, Damascus, killed hundreds of people. The U.S. and its allies blamed the Syrian government for that attack, which nearly sparked Western airstrikes before a negotiated diplomatic settlement saw Assad's government agree to give up its chemical weapons. Damascus denied the charges and blamed rebels of staging the incident.

Before the August attack, there have been several incidents of toxic gases being used. Britain, France and the U.S. have spoken about chemical weapons use in the central city of Homs, Damascus and elsewhere.

A U.N. weapons inspectors' report released in December identified four locations where chemical weapons likely had been used in 2013: Khan al Assal outside Aleppo, Jobar in Damascus' eastern suburbs, Saraqueb near Idlib in the northwest and Ashrafiah Sahnaya in the Damascus countryside. In two cases, inspectors reportedly found ``signatures of sarin,'' a nerve agent.

The Syrian National Coalition called on the U.N. to conduct a ``quick investigation into the developments related to the use of poisonous gas against civilians in Syria.'' The coalition also claimed that another chemical weapons attack Friday struck the Damascus suburb of Harasta, though state media did not report on it.

The chemical weapons attack in August caused an international outcry. A coalition formed to eliminate the weapons and now aims to remove and destroy 1,300 metric tons of chemicals held by the Assad government by June 30. Syria's government missed a Dec. 31 deadline to remove the most dangerous chemicals in its stockpile and a Feb. 5 deadline to give up its entire stockpile of chemical weapons. Assad's government cited security concerns and the lack of some equipment but has repeated that it remains fully committed to the process.

Meanwhile, violence continued Saturday elsewhere in Syria. In the northern city of Aleppo, Syria's largest and one-time commercial center, the Observatory and state television reported intense clashes, mostly near a main intelligence office in the city's contested neighborhood of Zahra.

Syrian state news agency SANA reported earlier Saturday that several mortar shells hit the government-held neighborhoods of Hamidiyeh and Khaldiyeh, killing at least six people and wounding 15.

Aleppo became a key front in the country's civil war after rebels launched an offensive there in July 2012. (AP)