Beirut (AFP) - More than 240,000 people, including 12,000 children, have been killed in Syria's conflict which broke out in March 2011, a monitoring group said Thursday.

The Syrian Observatory for Human Rights said it has documented the deaths of 240,381 people, up from its tally of 230,618 announced on June 9.

The latest toll compiled by the Britain-based group shows that 11,964 children were among 71,781 civilians killed in Syria.

At least 88,616 regime forces were killed -- or one thirds all deaths documented by the Observatory -- including 50,570 soldiers and the rest allied fighters.

The monitor, which relies on a wide network of sources on the ground, put the death toll for rebel fighters at 42,384 and said 34,375 foreign jihadists have also been killed in Syria.

The identity of another 3,225 people killed in the conflict remains unknown, according to the Observatory.

The fate of 30,000 people who have gone missing in Syria, including 20,000 said to be held in Syrian jails, was not documented in the toll.

It also did not take into account the fate of thousands of loyalist forces held by rebel factions or by the Islamic State jihadist group.

The Syrian conflict began with anti-government protests before spiralling into a multi-front war after a brutal regime crackdown.