Three Christians in the northern city of Mosul, Iraq, were killed within the short span of 24 hours on Tuesday, an Iraqi news agency reported.

A man and his father were shot dead at their workplace, while in another district unknown gunmen forced their way into a pharmacy and killed a Christian assistant who worked there, according to Aswat al-Iraq news agency.

"The gunmen fled to unknown place," the source told Aswat al-Iraq, without giving further details.

Mosul is the capital of Ninewa province and is located some 250 miles northwest of Baghdad. The city is a historic centre for Assyrian Christians, who view it as their ancestral homeland. It is home to the second-largest community of Christians in Iraq, after Baghdad.

The original city of Mosul lies on the west bank of the Tigris River, opposite the ancient biblical city of Nineveh on the east bank. Mosul contains the tombs of several Old Testament prophets including Jonah and Nahum.

Although Assyrians are the indigenous people of modern-day Iraq - tracing their history in the region back some 6,000 years - they are denied their most basic human rights and are the target of incessant attacks.

In recent years, Christians in Iraq have suffered increasing hostility from the Sunni al-Qaeda in Iraq terrorist group and by the Shiite militias.

Kidnappings, death threats, church bombings, and murders have become a regular part of life for the Christian community threatened with extinction in Iraq.

Prior to the 2003 US-led Iraq war, there was an estimated 1.4 million Christians in Iraq. Now the number has plummeted to less than half a million.

Christians, in response to persecution and instability, have fled Iraq in droves, making up nearly half of the refugees leaving the country even though they make up only three per cent of the population, according to the UN High Commissioner for Refugees.

Recently, the Iraqi Parliament passed a new provincial election law that would make life even harder for Christians.

The new law drops Article 50, which reserves a quota of the seats in the provincial councils for minorities. Without the quota system, Christians and other minorities fear that they will now have no voice in their country.

"We do not want to immigrate to the US or Britain - we want to stay in Iraq and have our representatives in both the provincial councils and the legislature," said the Rev Louis al-Shabi, a preacher at a Chaldean church in Baghdad, according to The Associated Press.

"We want to be treated equally as Iraqis living with the Muslims and other nationals in a united brotherly spirit."

The United Nations as well as Iraqi Christians in the United States have urged the Iraqi Parliament to reinstate Article 50.