CAIRO (Reuters) - Egyptian police deployed at churches across the country with orders to use live ammunition to protect Coptic Christians over their Christmas holiday on Tuesday, the Interior Ministry has said.

Dozens of churches and Christian properties were attacked in August, the month after the army overthrew Islamist President Mohamed Mursi.

Since then, although wider reprisals against Christians have been infrequent, sectarian rhetoric from Islamists against Christians, who make up about 10 percent of Egypt's population, has intensified and the authorities are on alert for any attack.

Mursi's relations with the Coptic church during his year in office were poor. Coptic Pope Tawadros II had accused the freely elected Islamist of neglecting the Coptic community.

Tawadros supported army chief Abdel Fattah al-Sisi's overthrow of Mursi, and appeared with a top Muslim cleric and others when the general announced Mursi's removal on July 3.

As part of its widening crackdown against the movement since Mursi's overthrow, the state designed his Muslim Brotherhood a terrorist organisation after a suicide bombing on a police compound in the Nile Delta last month that was claimed by a militant Islamist group.

The Brotherhood denies any links to violence.

Five to 10 police officers will be deployed to each church, where they will set up cordons to prevent cars from parking along the perimeter, sources said.

Plainclothes officers and counter-terrorism specialists will be on the streets near churches, along with "combat units" on roving patrols. Bigger teams will be deployed to the country's largest churches.

"If police confirm there is a presence of any terrorist elements, they will use live rounds," an Interior Ministry official told Reuters, speaking on condition of anonymity.

Interim head of State Adly Mansour visited the Pope on Sunday ahead of Tuesday's Christmas holiday, a gesture of symbolic importance that could help bolster Christian support for the army-backed roadmap ahead of a Jan. 14-15 referendum on a new constitution.

The visit "reflected the state's appreciation for the great patriotic role they (Egypt's Copts) played in countering attempts to sow seeds of division among Egyptians", the presidency said in a statement.

An attack by gunmen in October that killed four wedding guests outside a church in Cairo stoked fears that Christians would become scapegoats in Egypt's upheaval, held responsible by Islamists for backing Mursi's fall.

New Year's Eve marked the third anniversary of a bombing at a Coptic church in Egypt's second city of Alexandria, days ahead of the Christmas holiday, that killed 23 people and was the deadliest attack on a church in years.

(Reporting by Maggie Fick; Editing by Alison Williams)