The Taliban and its rival, the Islamic State (ISIS/ISIL), have launched competing claims for a deadly terrorist attack that occurred Monday in the Afghan capital of Kabul, reports NBC News.

Earlier this month, the U.S. Department of State reported that Taliban jihadists replaced ISIS fighters as the world’s chief perpetrators of terrorist assaults last year, with 1,093 individual attacks.

Various news outlets report that a suicide car bomb struck a minibus Monday carrying guards working for the embassy of Canada, killing 14 Nepalese nationals and injuring several others.

ISIS established its branch in Afghanistan, known as the Khorasan province (IS-KP/ISIL-K), in January 2015, less than a year after President Barack Obama declared an end to the U.S. combat mission in Afghanistan. Khorasan is an ancient name for a region that covers Afghanistan, Pakistan, and some of the surrounding countries.

The Taliban has been engaged in turf battles with ISIL-K, competing for influence and recruits in Afghanistan.

Khorasan province reportedly issued an official statement taking credit for the attack with a picture of the alleged bomber.

NBC News notes:

If true, the claim would mark the first major ISIS attack in the Afghan capital. Kabul has been stricken by violence from the Taliban but largely immune to ISIS’ creep in other parts of the country.

The Taliban quickly threw water on the claim, saying it had specially trained and deployed a suicide bomber Monday to target U.S. and NATO officials.

“This ISIS claim seems rubbish,” Zabihullah Mujahid, a Taliban spokesman, told NBC News. “They [ISIS] don’t have the courage to carry out such an attack in an important area like this.”

NBC News acknowledged that the Taliban is known for exaggerating claims following terrorist attacks.

Currently, Islam adherents across the world are celebrating the Muslim holy month of Ramadan, a period when radical Islamic terrorist groups such as ISIS and the Taliban intensify their calls for Muslims to engage in jihad and become martyrs.

Last year, a spate of high-profile terrorist attacks took place in Tunisia, Kuwait, and France following ISIS’s Ramadan message, which urged Muslims to carry out massacres in the name of Islam.

For ISIS, Ramadan coincides with the declaration of its so-called Caliphate in June 2014. Muslims abstain from eating, drinking, smoking, having sex, and other physical needs each day during the holy month, starting from before the break of dawn until sunset.

Despite ISIS’ presence in Afghanistan, the Taliban remains the most prominent jihadist group in the country.

Some Taliban fighters have defected to ISIL-K.

However, earlier this year, various news agencies reported that some of those defectors had switched their allegiance back to the Taliban, claiming they were repelled by the brutal acts committed by the Khorasan province, namely beheadings.

The Taliban has committed savage acts of violence in recent years, including skinning a man alive after ripping out his eyes.