The Islamic State (ISIS/ISIL) claimed responsibility for carrying out a terrorist attack on a church in the Muslim-majority Russian republic of Chechnya that killed three and wounded three others over the weekend.

Radio Free Europe/Radio Liberty reported on Saturday, the day of the terrorist attack:

Russia police shot dead four gunmen who attacked a Russian Orthodox church in the mostly Muslim Russian republic of Chechnya. Russia’s Investigative Committee said in a statement that two police officers were killed and another two wounded in the May 19 clash that also left one churchgoer dead and another one wounded. The committee added that the four assailants were armed with guns and knives.

On Sunday, ISIS claimed responsibility for the attack, which bore the hallmarks of similar recent assaults linked to the terrorist organization.

“Islamic State fighters executed an attack on ‘Michael’ Church yesterday in Chechnya’s capital, Grozny,” the jihadist groups claimed through its Amaq news agency without providing specific evidence to support its allegation, Reuters noted.

The attack came two days after the start of the Muslim holy month of Ramadan when Islamic terrorists believe it is exceptionally blessed by God to engage in jihad and die a martyr.

Islamic terrorist attacks tend to increase during the holy month.

Last week, Breitbart News reported that ISIS had enhanced its terrorist activities in areas outside the group’s former caliphate in Iraq and Syria.

Although the U.S.-led coalition and local forces have nearly defeated ISIS in Iraq and Syria, the group remains a threat, American officials have repeatedly warned.

Russian nationals made up the largest number of jihadists from non-Muslim nations who joined ISIS in Iraq and Syria, according to data from the U.S.-based intelligence consulting firm known as the Soufan Group (TSG).

The consulting firm reported that at least 2,400 foreign fighters from Russia had traveled to engage in jihad on behalf of ISIS as of April 2017.

TSG designated Russia the third country in the world with the most foreign fighters in the Middle East at the peak of ISIS’s power in the region in 2015, only after Muslim-majority Tunisia and Saudi Arabia, respectively. Moscow has expressed concern about battle-hardened jihadists returning to Russia.

ISIS has made several threats against the soccer World Cup, expected to take place in Russia (starting June 14) during Ramadan.

“We are in Russia,” cautioned the terrorist group in a message along with an image depicting a suicide bomber and a Russian soccer stadium.

Days before the attack on the church, ISIS North Caucus blew up a Sufi shrine in the Muslim-majority Russian republic of Dagestan.

In the first four days of Ramadan, which began Thursday, terrorist groups such as ISIS and the Taliban have carried out an estimated 12 attacks, killing at least 41 people and injuring 102, a Breitbart News tally shows.