Estimates for the number of Britons thought to have been killed or captured in the enormous terrorist attack against Israel on Saturday has risen to 17 from an earlier figure of “over ten”.

A government source has told British state broadcaster the BBC that children are among the seventeen British citizens now thought to be among the dead and missing in Israel. Hamas terrorists attacked southern Israel on Saturday, striking army observation posts, taking out communication networks, deluging the area in rocket barrages, and launching waves of fighters by land and air.

Over 1,000 in Israel are now said to have been killed, many in the most barbaric of circumstances, and tens of dozens are thought to have been taken as hostages, an insurance policy by Hamas terrorists to save themselves from retribution for the attack. Citizens from at least 17 nations worldwide are thought to be among the victims, but the scale and nature of the terrorist attack has made positive identification difficult, reflected by the British government admitting at first it did not know how many of its own citizens were impacted.

Now the earlier figure of “over ten” Britons has been revised to a more certain 17 victims, among them children, known fatalities, and those feared captured. In addition to casualties, the British government has also previously said a “significant number” of British citizens were otherwise caught up in the fighting.

Among those known killed are 20-year-old Nathaniel Young, who grew up in London, and was serving in the 13th Battalion of the Israel Defence Force (IDF). He was killed in fighting on Saturday and was buried at the Israel national cemetery on Mount Herzl this week.

Another British citizen reported killed is Bernard Cowan, a grandfather who had grown up in Glasgow before moving to Israel with his family. The BBC reported Cowan lived “just metres away from the Gaza border”.

34-year-old photographer Daniel Darlington from Manchester, England was visiting Israel as a tourist when he was killed by terrorists on Saturday alongside his German citizen travelling companion Carolin Bohl, reports the Manchester Evening News.

Among those possibly taken hostage is British carpenter Jake Marlowe, who was working security at a music festival when it was attacked by terrorists. According to The Independent, he left voice notes to his family telling them he was trying to evacuate attendees on a quad bike before his phone stopped responding to calls.