ISIS steps up attacks against Christians

NORTH SINAI, Egypt (CNN) ISIS is stepping up attacks against Christians in the north Sinai region of Egypt.

Many Christians are fleeing their homes to safer areas of the country.

Some of them say the government isn't doing enough to stop the attacks.

Are you Christian? The last three words Nabila Halim's son ever heard.

Then a gunshot. Halim ran to her dying son, recalling how ISIS militants threw her into the street, killed her husband then looted her home before setting it on fire.

Halim is one of dozens of Christian families fleeing north Sinai to Ismailia on the shores of the Suez Canal…

She says her son, Medhat, knew the danger but refused to leave.

"If the terrorists kill me, I will have the honor to die a martyr and be with Jesus," she recalls him saying.

ISIS claimed responsibility for the deaths of 7 Christians in north Sinai since the end of January - some in broad daylight.

In a recent video the terror group issued a threat saying, "It's obligatory to target Egypt’s Christians and ruin their lives."

ISIS militants battle Egypt’s military for control of the coastal desert region. The army claims the upper hand, despite this latest exodus…

ISIS's attacks in Egypt aren't confined to the Sinai. In December, a bomb at a church in Cairo killed at least 25 people, including many children. ISIS also claimed responsibility.

The government is failing to protect Christians, says Magdy. He's the latest arrival from north Sinai.

He requested CNN conceal his identity because he has family left behind.

"We were told to either convert to Islam or pay a tax. We refused, so ISIS now tries to kill us," Magdy said.

A familiar ISIS threat…and a stark choice for Christians living in the north Sinai.