Aleppo's woman sniper, Guevara (Reuters)

A woman English teacher has turned sniper against Syrian troops to avenge the deaths of her children who were killed in a government airstrike.

Guevara, named after the Argentinian Marxist revolutionary, took up the fight against Syrian president Bashar al-Assad's forces after her 10-year-old daughter and seven-year-old son were killed in an air raid in the family home in Aleppo.

"My boy used to be frightened of the bombs, and ask me what was happening. I said 'I promise that I am going to defend your future'. Now, I will not forget my children's blood and I promise to take revenge," she told the Telegraph.

She said she had learned to develop speed, caution, intelligence and patience as a sniper. In battle, she wears a grey jumper dress, hijab and green khaki trousers and targets soldiers through a peephole. Although a female sniper is extrtemely rare in Syria's conservative Muslim society, she has earned the respect of her 30 fellow fighters in her Free Syrian Army division in Aleppo.

As Guevara recounts how she killed soldiers, hitting at them at least four or five times, her tone became almost fanatical. "It makes you feel good. Whenever I hit one I shout 'Yes!'," she said.

Guevara, 36, admitted that she enjoyed fighting. "When I see that one of my friends in my katiba [rebel division] has been killed, I feel that I have to hold a weapon and take my revenge," she explained.

But she still wakes up at night sometimes crying in her sleep at the horror she has witnessed and for the loss of her children.

Born in Palestine, Guevera learned how to use a gun in a military camp in Lebanon controlled by Hamas militant group. She started fighting against Assad's regime many years ago - before the uprising began. Joining a secret political party for Palestinians, Guevara attended meetings to discuss how to oust Assad.

When the Arab Spring reached Syria in March 2011 she took part in the protests against the repressive government. She said that she had left her first husband for not being sufficiently "revolutionary".

Her second husband, commander of her brigade, refused to let her fight on the front line until Guevara threatened to leave him too.