The Foreign Office is urgently investigating reports that a soldier thought to have been captured by Hamas fighters in Gaza is a British Israeli.

Channel 4 News reported that Lieutenant Hadar Goldin, 23, is from a family of British Jewish immigrants.

"We are aware of these reports and we are urgently looking into them," a Foreign Office spokeswoman said.

Lt Goldin disappeared as a humanitarian ceasefire brokered by the United States and the United Nations collapsed into more bloodshed and violence just hours after it was supposed to take effect.

Israeli army spokesman Lieutenant Colonel Peter Lerner said that the apparent abduction took place when Palestinian gunmen emerged from their network of tunnels, with at least one fighter detonating an explosives vest.

In the ensuing mayhem, Lt Goldin was apparently captured and taken back into Gaza through a tunnel, while another two soldiers were killed.

"We suspect that he has been kidnapped," Col Lerner said.

An Israeli official said the apparent abduction marked a "very dangerous escalation of violence" and that there would be no three-day ceasefire.

On its official Twitter feed, an IDF spokesman said: "2nd. Lt. Hadar Goldin, 23 from Kfar Saba, is the soldier suspected to be kidnapped by Hamas earlier today.

"We suspect that a group of Hamas terrorists, including a suicide attacker, kidnapped 2nd. Lt. Goldin at 9:30am and dragged him into a tunnel.

"Hamas terrorists killed two IDF soldiers during the suspected kidnapping of 2nd Lt. Goldin this morning."

Israel and Hamas blamed each other for the breakdown of the ceasefire - which saw fighting break out again less than two hours after a supposed three-day truce started at 8am local time (6am BST).

Palestinian officials said that Israeli shelling around the town of Rafah had killed at least 35 Palestinians and injured about 200 while the Israelis said that militants had fired eight rockets and mortars across the border into Israel.