The Islamic State group on Saturday claimed responsibility for an attack at a mosque of the minority Ahmadi Muslims in Bangladesh, in which the suspected bomber died and at least three others were injured.

US-based monitoring organisation SITE reported that the ISIS group, which has claimed responsibility for a number of recent attacks in Bangladesh, said it had targeted worshippers during Friday prayers.

The bomber detonated an explosive belt at a mosque of the "polytheist Qadiani sect," a derogatory term for Ahmadi Muslims; the monitoring organisation quoted ISIS as saying.

According to the statement "dozens" of worshippers were injured or killed at the mosque in the north-western town of Bagmara, but police said on Friday only three had been injured.

The bomb blast at the Ahmadiyya Muslim Jamaat mosque in Bagmara, some 250 kilometres (150 miles) from the capital Dhaka, occurred as nearly 100 people were gathered for Friday prayers, police said.

ISIS has claimed a series of recent attacks in Bangladesh, including the shooting of three foreigners, two of whom died, and the killing of a Sufi Muslim shrine chief in November.

The jihadists also claimed an attack at a Shiite mosque in the north of the country last month in which the muezzin was killed and three worshippers injured -- though some experts have expressed scepticism about the claims.

Police blame the home-grown militant group Jamayetul Mujahideen Bangladesh (JMB) for the recent violence while Prime Minister Sheikh Hasina's government accuses the main opposition party and its Islamist ally of trying to trigger anarchy. The parties deny the claims.

Analysts say Islamist extremists pose a growing danger in conservative Bangladesh and that a long-running political crisis has radicalised opponents of the government.