A Kurdish military official said on Monday he had evidence Islamic State militants have used chlorine as a chemical weapon against peshmerga forces three times in northern Iraq.
General Aziz Waisi, who said his forces were exposed to the chemical, said the insurgents had used chlorine in a December attack in the Sinjar area and in two others in January west of Mosul.
The two earlier purported chemical weapon assaults reportedly resemble one claimed Saturday by Kurdish officials who say an independent laboratory concluded the militants used chlorine gas against its peshmerga forces in a January 23 truck suicide attack. However, their claims were not immediately verified by international authorities.
Iraqi officials and Kurds fighting in Syria have made similar allegations about the militants using the low-grade chemical weapons against them. The Islamic State group, which controls a third of Syria and Iraq in its self-declared caliphate, has not commented on the claims.
General Wesi, in charge of a Kurdish special forces brigade, told journalists Monday that authorities declined to immediately discuss the attacks when they happened out of fears of causing a panic.
Kurdish officials have offered footage of the aftermath of a December 26 attack, which shows fighters coughing and pouring water over their heads after a suicide truck bombing that authorities say wounded some 60 men.
Captain Mohammad Sewdin, who was leading the Kurdish special forces unit targeted in the December attack, told the Associated Press he was temporarily blinded for six hours after the attack and coughed up blood. He and others he said were hospitalized.
On Saturday, the Kurdistan Region Security Council offered video and lab results it said proved the Islamic State group used chlorine in a January 23 suicide truck bomb.
There has been no independent confirmation of any of the Kurds' claims.
Elsewhere Monday, Iraqi Interior Minister Mohammed Salem al-Ghabban said the offensive to retake the Islamic State-held city of Tikrit will be on hold until civilians in Saddam Hussein's hometown can flee and roadside bombs can be cleared.
Military officials in Tikrit said there was no fighting on Monday in the city that was home to more than 250,000 people before it was overrun last year.
Government forces are in control of most of the northern Qadisiya district as well as the southern and western outskirts of the city, trapping the militants in an area bounded by the river that runs through Tikrit, according to Reuters.
Speaking to reporters from the nearby city of Samarra, he said Islamic State militants booby-trapped roads and buildings leading into Tikrit, slowing the Iraqi forces, aided by Iranian advisers.
Al-Ghabban offered no timeframe for the advance to resume, saying that is being “left to the field commanders.”
Though Iraqi forces and allied militiamen may have the insurgents in a chokehold, officials are increasingly citing air power as necessary to drive out the remaining insurgents, according to a report by Reuters.
"We need air support from any force that can work with us against IS," Deputy Minister of Defence Ibrahim al-Lami told Reuters, declining to say whether he meant from the U.S.-led coalition or Iran, which is playing a role in the assault.
The U.S.-led coalition, which has been conspicuously absent from the offensive, continues to conduct airstrikes elsewhere in Iraq and Syria.
Coalition airstrikes helped Kurdish forces seize the villages of Wahda, Saada, and Khalid from Islamic State militants in the north -- part of a broader week-long offensive to drive the militants away from the oil-rich city of Kirkuk.
Shi'ite Turkmen fighters also clashed for a fourth day with Islamic State insurgents near the village of Bashir, south of Kirkuk.
In Baghdad, Special U.S. presidential envoy General John Allen addressed a meeting of Iraqi and foreign officials aimed at kicking off efforts to stabilise and rebuild territories retaken from Islamic State.
Bosnia arms donation
Meanwhile, Bosnia has donated more than 550 tons of surplus arms and ammunition to Iraq as part of its involvement in the U.S.-led coalition against Islamic State militants, the Balkan country's defense minister said on Monday.
The donation, made on request from the United States, comprises arms and ammunition produced decades ago, when Bosnia was part of the now-defunct Yugoslav federation, Minister Zekerijah Osmic told reporters. He did not rule out similar donations in the future.
Under its NATO and U.S.-sponsored defense reforms, Bosnia has to offload more than 16,500 tons of ammunition and more than 40,000 pieces of weaponry, a surplus left over after its 1992-95 war in which more than 100,000 people died.
Bosnia is not in the NATO alliance but hopes to join.
A lot of the surplus arms, kept in warehouses often close to human settlements, are becoming increasingly rusty and may pose a security risk for citizens, Osmic said.
Some material for this report came from AP and Reuters.