Spain is mourning Carme Chacón, the former defence minister who died on Sunday and was famously photographed in 2008 reviewing troops in Afghanistan while seven months pregnant.

Ms Chacón was found dead at her Madrid home, aged 46, after a neighbour had raised the alarm. A congenital heart problem was the likely cause of death.

She was Spain's first woman defence minister, symbolising the change of culture since the end of military rule.

Her son Miquel is eight years old.

In 2007 Ms Chacón also served as housing minister in the Socialist government led by ex-Prime Minister José Luis Rodríguez Zapatero.

Spanish politicians were among the many Spaniards who expressed shock and sympathy over Ms Chacón's sudden death.

Mr Zapatero said he was "heartbroken at the death of my comrade and friend".

He said "we feel emptiness, because of the enormity of this loss, for Spanish democracy and for all socialists".

The current Popular Party (PP) defence minister, Dolores de Cospedal, said "I deeply mourn the ex-minister". "My heartfelt condolences to her family, friends and the Socialist Party. RIP."

At the age of 37, and seven months pregnant, she visited Afghanistan, five days after being appointed defence minister.

She told Spain's El Pais daily "pregnant or not, I was clear that my first duty was to visit those who are able to put their lives at risk for higher values: for other people's freedom".

"A pregnant woman is not sick. Sure, it's harder when you're pregnant and on your feet all day. I wanted to express society's gratitude to those who put themselves in danger to bring peace to regions of conflict."

Spaniard Victor Orive-Martin tweeted the famous photo, in a tribute to Ms Chacón, calling her "a wonderful human being".