First minister Humza Yousaf’s in-laws are trapped in Gaza

Israeli Prime Minister Benjamin Netanyahu vowed “this is only the beginning” of retaliation against Hamas for terror attacks at the weekend, as a “complete siege” was declared to cut off electricity, food, water and fuel to the Gaza Strip.

Ten British citizens are missing or believed dead since the weekend, including Bernard Cowan, 57, from Newton Mearns, Glasgow, whose family said he was “murdered” in the unprecedented attack by Hamas on Saturday.

More than 700 people are thought to have died in the initial assault, as well as 500 Palestinians in a major counter attack on Gaza. Others have been taken hostage and transported to the territory.

Palestinians search for survivors after an Israeli airstrike on buildings in the refugee camp of Jabalia in the Gaza Strip (Photo by MOHAMMED ABED/AFP via Getty Images)

First Minister Humza Yousaf revealed his wife’s parents are trapped in Gaza after travelling there from Dundee last week to visit family.

Mr Yousaf, whose wife, Nadia El-Nakla, is of Palestinian descent, said the couple were “sick with worry” about her parents and said they did not know if they would “make it through the night”.

As aid organisations warned of a “humanitarian emergency on an unimaginable scale” an emergency Cobra meeting of the UK government was called.

Afterwards Foreign Secretary James Cleverly said Hamas terrorists were “shielding themselves among the Palestinian people”.

Israeli security forces inspect a car, damaged in a rocket attack from Gaza in Har Adar, a settlement northwest of Jerusalem, high in the hills close to the Green Line that separates the occupied West Bank from Israel. Photo: AHMAD GHARABLI/AFP via Getty Images

Meanwhile Mr Netanyahu told local and regional council heads in the south of Israel that the country’s response “will change the Middle East”, adding that “what Hamas will experience will be difficult and terrible”.

He said: “This is only the beginning...we are all with you and we will defeat them with force, enormous force.”

Nathanel Young, who was serving with the Israel Defence Forces (IDF), is the only British citizen confirmed to have died.

Photographer Dan Darlington is believed to be among the dead, after attending the music festival on the border with Gaza which was targeted by Hamas militants.

A total of 260 people were killed at the festival, while others were abducted.

Around 50,000 to 60,000 British nationals are believed to be in either Israel or Gaza, the government estimates, amid concerns for their safety.

Family and friends described Mr Cowan, who was said to be a Celtic fan, as the “kindest, most generous person”.

His brother, Colin Cowan, wrote on Facebook: "Yesterday my brother was murdered by the terrorist Hamas.

"He was the kindest, most generous person you would ever meet, and would go out of his way to help others. We are all heartbroken."

A statement from his family said Mr Cowan would be a “huge loss” to family and friends, as well as the Jewish community in Glasgow.

It added: "We are grieving the l

Israel declares ‘complete siege’ against Gaza as ‘only the beginning’ of retaliation