Dhaka (AFP) - Unidentified gunmen shot and wounded an Italian priest in northern Bangladesh on Wednesday, just weeks after two foreigners were killed in similar attacks blamed on hardline Islamists, police said.

Gunmen on a motorbike attacked the priest, identified as Piero Parolari, at close range as he was riding his bicycle in the northern city of Dinajpur, before fleeing, a police inspector said.

"Riding a motorcycle, unidentified attackers shot Italian priest Piero near the Dinajpur bus station in the morning," inspector Robiul Alam told AFP.

He said the priest was flown to Dhaka, 350 kilometres away, in an army helicopter in a "serious condition" and is being treated at a military hospital in the capital.

No one has yet claimed responsibility for the attack and no arrests have been made.

But it bore similarities to the recent murders of an Italian aid worker who was shot dead in Dhaka in September and that of a Japanese farmer, killed in the country's north days later.

In each of those attacks, three gunmen targeted the victims while riding on a motorcycle.

The Islamic State group claimed responsibility for the killings, while the jihadists also said they were behind a stabbing attack on a group of police in Dhaka this month that left one officer dead.

The government has rejected the claims, insisting IS has no presence in Bangladesh, which until recently was known as a mainly moderate Muslim nation. Police have instead blamed a banned local Islamist outfit.

Aged in his 60s, the priest has been based at Suihari Catholic Mission in Dinajpur for more than 30 years, according to another priest, Anthony Sen, who lives in the same city.

"He is also a doctor who works at St. Vincent Hospital run by the Catholic mission and at a government hospital in the city," Sen said.

The priest was "riding a bicycle at around 8:00 am (0200 GMT) when three attackers shot him at close range", Sen said.

"One of the bullets hit his neck. He bled a lot." Another priest, Sebastian Tudu, said the Italian also suffered injuries to his eyes. "Both his eyes have been bandaged. He may have been stabbed, but we are not sure," he told AFP.

The attack came as Bangladesh's highest court upheld the death sentences of two opposition leaders convicted for atrocities during the 1971 independence war against Pakistan - Ahsan Mohammad Mujahid and Salahuddin Quader Chowdhury - sparking fears of violence by their supporters.

Bangladesh has been reeling from rising Islamist violence in recent months, including a series of machete murders of secular bloggers and a publisher, attacks claimed by a local Islamist group.

A bombing of the capital's main Shiite shrine in Dhaka in October that left two people dead further heightened fears for minorities in the officially secular country.

Prime Minister Sheikh Hasina's government launched a crackdown on local Islamist groups after facing Western criticism of failing to stop the bloodshed.

The government accuses opposition groups of being behind the violence in an attempt to destabilise the country.