Syrian army shelling destroyed the centuries-old mausoleum according to activists and a monitoring group.
A monitoring group put the death toll in the latest airstrike at 28 civilians, including, once again, women and children.
A top figure in Isis' self-declared police force has been found decapitated in Syria, a monitoring group has claimed.
Syrian state media, a monitoring group and a local activist all reported that Nusra's Abu Hammam al-Shami was killed, but provided contradictory information on the circumstances.
Activists and a monitoring group said Isis had used the majestic Roman theatre in Palmyra to execute nearly two dozen pro-Assad foreign fighters on Wednesday.
In Syria's devastated Aleppo city, however, more than 300 civilians have been killed in a three-week surge of fighting and bombardment, a monitoring group said on Saturday.
But Helen Bialer, chairwoman of the Brookfield Landfill Citizens Advisory Committeee, a monitoring group, called such an effort unnecessary and expensive.
Five members of Syria's security forces were killed in the blast, which was followed by heavy clashes between rebels and forces loyal to Assad, a monitoring group said.
The Syrian Observatory for Human Rights, a monitoring group based in Britain, said that at least 23 people were killed in Thursday's Israeli strikes across Syria.
Why aren't things getting better?' " said Rachelle Jackson, the director of sustainability and innovation at Arche Advisors, a monitoring group based in California.
The Syrian Observatory for Human Rights, a monitoring group, said the targets included a radio station east of Hasaka owned by the Y.P.G.
