At least 15 civilians have been killed in an apparent cluster bomb attack on an Isis held village in eastern Syria, activists say.

A jet from an unidentified air force dropped the outlawed weapons on Doblan on the Euphrates River on Tuesday, both activist run media outlet Deir Ezzor 24 and monitor Justice For Life said.

The UK-based Syrian Observatory for Human Rights put the initial toll at 30. Head of Deir Ezzor 24, Omar Abou Layla, said he expected the number of reported deaths to increase.

Account of woman captured by Isis who was given her cooked son to eat after three days of starvation

Cluster munitions are particularly deadly because they release sub-munitions or bomblets on impact which can land over areas as large as a football pitch.

They are banned under international law because of the indiscriminate damage they cause.

US-led coalition planes, as well as the Syrian and Russian air forces, are all known to fly sorties over the area.

Russia was heavily criticised by the international community for using cluster bombs during the siege of Aleppo last year.

In pictures: Isis' weapons factories Show all 11 1 /11 In pictures: Isis' weapons factories In pictures: Isis' weapons factories A mortar round fin manufactured by Isis in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis rocket components discovered in Gogjali, Mosul, Iraq in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortars discovered near Karamlais, Iraq, in November 2016 CAR In pictures: Isis' weapons factories An Isis rocket launch frame in Qaraqosh, November 2016 Conflict Armament Research In pictures: Isis' weapons factories A memo from Isis' COSQC on quality control at a manufacturing facility in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Electrically-operated initiators manufactured by Isis in forces Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortar tubes at a manufacturing facility in Karamlais, November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis mortar production facility discovered in Gogjali, Mosul, in November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis weapons manufacturing facilities near Mosul in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Stocks of French-manufactured Sorbitol, Latvian potassium nitrate and Lebanese sugar at an Isis weapons factory in Iraq Conflict Armament Research In pictures: Isis' weapons factories A destroyed Isis weapons facility in Qaraqosh, Iraq, November 2016 Conflict Armament Research

Human Rights Watch says they have been widely used across Syria since Russia began giving air support to President Bashar al-Assad’s forces in September 2015.

The strike on Doblan comes a day after at least 57 were allegedly killed after US-led coalition war planes hit a building in al-Mayadeen used by Isis to imprison dissenters.

A spokesperson for the coalition said it is investigating the reports.