Two suspects arrested after gunmen storm mosque and open fire on praying worshippers, killing one and wounding three.

ISIL claimed responsibility after gunmen killed one Shia Muslim and wounded three others at a mosque in Bangladesh, a US monitoring website said on Friday. It was the second assault targeting the religious minority in a month.

However, a Bangladeshi official denied that Islamic State of Iraq and the Levant was operating in the South Asian nation of 160 million people.

Three masked attackers entered the Imam Khomeini mosque in Haripur village and began shooting indiscriminately before escaping, witnesses told Al Jazeera. At least 20 people were saying evening prayers at the time on Thursday.

Two suspects were arrested in connection with the attack in Bogra district, 125 kilometres northest of the capital Dhaka, according to local media reports.

Bangladesh festival overshadowed by attacks

The US-based intelligence group SITE, which monitors the communications of armed groups, said ISIL had taken responsibility online for the mosque assault.

But Muntasirul Islam, deputy commissioner of Dhaka Metropolitan Police, said he doubted the veracity of ISIL’s statements, adding past claims by the group could not be corroborated.

“We have spoken to the media before, categorically denying ISIL’s claims in the past. Investigating agencies did not find any relations with the murder of bloggers and foreign nationals to outside terrorist organisations,” Islam told Al Jazeera.

Seventy-year-old Moazzem Hossain – the mosque’s muezzin, the man who calls Muslims for prayer – died shortly after being admitted to a local hospital.

ISIL has claimed responsibility for the murder of two foreign nationals in recent months, as well as the grisly killings of several bloggers.

On October 24, ISIL claimed responsibility for a series of blasts targeting Shia Muslims in Dhaka during a religious procession, killing one person.

But Islam told Al Jazeera that local armed groups were behind past attacks, not ISIL. “They use the name of Islamic of State [of Iraq and the Levant] to attract media attention,” he said.

Bangladesh’s Prime Minister Sheikh Hasina said those carrying out attacks are not real Muslims.

“Killing people during prayers at mosques is not a job done by a true Muslim … nor is suicide a job of a true Muslim,” she was quoted as saying.

Amid rising threat to foreign nationals, Australia on Friday asked its citizens to voluntarily leave Bangladesh, adding that it would withdraw government-funded volunteers by December 31.

Additional reporting by Mahmud Hossain Opu