Reports from Mali say Islamists have destroyed at least two remaining mausoleums in the historic city of Timbuktu.
Since taking control of northern Mali earlier this year, militants have demolished seven of the 16 mausoleums listed as UN world heritage sites.
Some of the shrines date back to the 14th century.
But rebel groups, many with links to Al Qaeda, consider the traditional Sufi Islamic shrines as idolatrous.
Residents trapped in Timbuktu have called news outlets and said fighters, some armed with pickaxes, have once more started attacking tombs in the city.
They said at least two previously untouched tombs were destroyed over the weekend.
The UN Security Council last week authorised an Africa-led force to retrain Mali’s defeated army with the aim of retaking the territory controlled by hardline Islamists.
One Timbuktu resident claimed a fighter who took part in the latest tomb-smashing said they wanted to prove to the world they would not be swayed by the threat of foreign military intervention.
Around 400,000 people have fled their homes in Mali this year.
The rebellion was launched by separatist Tuareg rebels but has since been hijacked by better armed and funded Islamists operating alongside Al Qaeda fighters in the Sahara.
Another group, Ansar Dine, is officially in control of Timbuktu.
this breaks my heart