The Taliban has turned on Christians with a vengeance for the ongoing army offensive against the Islamic militants in Pakistan.

Furious over the US and Pakistan's military operations in Swat Valley, the Taliban attacked a Christian colony, causing fear and panic among its members and forcing them to join 200,000 others fleeing the town.

In Karachi, a growing foothold of the Taliban, there were reports of an attack on a Christian slum by extremists.

Pastor Salim Sadiq of Holy Spirit Church in Karachi told Christian Today that Christian homes were pounded by Islamic extremists who have vowed to avenge for "the suffering of their brotherhood in NWFP area".

"They barged into our homes shouting 'death to infidels' and beat us, hurling murderous threats if we don’t convert to Islam," Sadiq recalled.

He lamented, "Christians have no voice here. We have been suffering from ages like this under the staunch Muslim militants who rape our daughters, burn our churches and raze down our homes."

"Although the majority Muslims need not worry about the military offensive on Taliban, for Christians who are so microscopic and fragile, it is a serious concern, as it will amplify the Taliban and foment dreadful violence on us," he added.

There is rising fear that Taliban insurgents will spread to the main city with Swat being just 100 miles from Islamabad, Pakistan's capital.

Sadiq predicts that a violent wave on Christians is imminent.

The Rev Richard D'Souza of St Jude Church in Karachi, said last Thursday that "there is a lot of feeling of fear by all the minorities", according to The Associated Press.

After young Christians protested the anti-Christian graffiti on St Jude Church's walls, 25 men went on the rampage, beating Christians, pelting stones and setting fire to homes. An 11-year-old boy was killed during the violence.

"The police never helped. None of us had weapons. The police just stood there," 26-year-old Imran Masih, who spent 10 days in the hospital after a bullet pierced his neck, told AP.

The United Nations, meanwhile, said it had registered more than 800,000 Pakistanis fleeing fighting between the army and the Taliban.

Calling for massive aid operation, UN High Commissioner for Refugees Antonio Guterres warned that the plight of displaced people may lead to more conflict.

"If you are not able to cope with the challenges posed by such an overwhelming number of people displaced, in communities that have not the economic capacity to absorb them, and if the very serious humanitarian response is not organised, this population will become a huge factor of destabilisation."

On Monday, Prime Minister Yusuf Raza Gilani said Pakistan's army will finish its offensive against Taliban militants in the Swat valley and ensure peace.