Emily Thornberry has warned of repercussions in the Middle East after what appeared to be an Israeli-linked attack in Lebanon and Syria killed nine people, including members of the militant group Hezbollah, and injured nearly 3,000 others.

The Labour MP, recently elected as chairwoman of the UK’s Foreign Affairs Select Committee, said she expected Israel’s allies to be asking the country “What on earth are you doing?” after hundreds of pagers exploded on Tuesday afternoon.

The pagers had reportedly been acquired by Hezbollah in an attempt to evade Israeli intelligence. Those injured include the Iranian ambassador, officials said.

An eight-year-old girl was also killed during the explosions.

Hezbollah and the Lebanese government have blamed Israel for what seemed to be a sophisticated remote operation.

The UK Foreign Office urged “calm heads and de-escalation” after the incident.

An FCDO spokesperson said: “We continue to monitor the situation in Lebanon closely and the UK is working with diplomatic and humanitarian partners in the region. The civilian casualties following these explosions are deeply distressing.

“We urge calm heads and de-escalation at this critical time.”

Speaking to Sky News on Wednesday morning, Ms Thornberry said: “We are really concerned about what is happening now in Lebanon.

“I think the big question is: why? Why is this happening now? And what will the result of that be?

“It seems to be yet another escalation of the conflict which is happening in the Middle East, which will affect all of us. And it is very worrying indeed, of course it is, and what the response will be? And is this the first step, and what will Israel do next? Is it part of a larger plan?

“It is very worrying and I would certainly be expecting Israel’s friends to be speaking very seriously to them, and saying: ‘What on earth are you doing? Why is this happening now?’”

Fabian Society conference
Ms Thornberry was elected as chair of the Foreign Affairs Select Committee (Maja Smiejkowska/PA)

Hezbollah said in a statement on Wednesday morning that it would continue its normal strikes against Israel “as in all the past days” as part of what it describes as a support front for its ally, Hamas, and Palestinians in Gaza.

In August, Foreign Secretary David Lammy urged UK nationals in Lebanon to leave the country amid growing tensions between Israel and Hezbollah, in the wake of the ongoing conflict in Gaza.

Hezbollah began firing rockets over the border into Israel on October 8, the day after a deadly Hamas-led terrorist attack in southern Israel triggered a massive Israeli counter-offensive and the ongoing war in Gaza.

Since then, Hezbollah and Israeli forces have exchanged strikes on an almost daily basis, killing hundreds in Lebanon and dozens in Israel, and displacing tens of thousands on each side of the border.

The pagers targeted in the attack had been acquired by Hezbollah after the group’s leader told members in February to stop using mobile phones, according to Associated Press.

Taiwanese company Gold Apollo said it had authorised its brand on the pagers, but they were manufactured by a company based in Budapest.

The AR-924 pagers were manufactured by BAC Consulting KFT, based in Hungary’s capital, according to a statement by Gold Apollo.

It said: “According to the co-operation agreement, we authorise BAC to use our brand trademark for product sales in designated regions, but the design and manufacturing of the products are solely the responsibility of BAC.”