The US embassy in Turkey on Saturday warned of “credible threats” to tourist areas in Istanbul and the resort city of Antalya, intensifying fears in a country hit by four suicide bombings this year.

The fresh alert comes a day after Israel reissued a warning to its citizens to avoid Turkey or “leave as soon as possible”, citing an imminent risk of an attack.

The US alert comes three weeks after a suicide bomber struck a popular shopping street in the heart of Istanbul — killing four people and injuring dozens — in an attack which authorities blamed on the Islamic State group.

“The US Mission in Turkey would like to inform US citizens that there are credible threats to tourist areas, in particular to public squares and docks in Istanbul and Antalya,” read an emergency travel warning published on the US embassy’s official website.

A series of attacks in the capital Ankara and Istanbul — blamed on Kurdish militants or jihadists — have left 79 people dead since January and created jitters among residents and tourists alike.

The March 19 attack in Istanbul left four Israelis and an Iranian dead, while a January attack in city killed eleven German tourists.

Many countries have already issued travel warnings, but Israel repeated its call for citizens to leave the country on Friday following a fresh assessment.

“Following a situational assessment, we are reiterating and sharpening the high level of threat in Turkey,” Israel’s counter terrorism bureau said.

“There are immediate risks of attacks being carried out in the country, and we stress the threat applies to all tourism sites in Turkey.”

– Iran, Ukraine tourism hopes –

Istanbul — Turkey’s biggest city and historic centre which straddles Europe and Asia — and Antalya with its turquoise Mediterranean waters, are both firm tourist favourites.

However the series of suicide attacks as well as a spat with Russia have hit the tourism sector hard.

Russia ordered its travel agencies to stop selling trips to the country, a major destination for Russians, after Turkey shot down one of its jets on the border with Syria.

The tourism ministry has reported visitor numbers plunged 10 percent in February, even before the latest Istanbul attack and a car bomb which killed 35 people in Ankara.

Local media reported this week that Turkey was planning to increase flights to Iran as part of its bid to woo visitors from elsewhere.

The state-run Anatolia news agency reported Turkish tour operators would focus their attention on Ukraine instead of Russia, with Turkey hoping to attract one million visitors from its Black Sea neighbour to compensate for losses elsewhere.

Tourism is a mainstay of the Turkish economy and according to official statistics, foreign tourism brought in almost $31.5 billion in revenues in 2015.

– ‘Crippled logic’ –

The Islamic State group is suspected of having carried out several of the recent attacks, including one which left 103 people dead at a peace rally in Ankara in October last year.

However two other Ankara suicide bombings this year have been attributed to a radical Kurdish group which Ankara says is linked to the outlawed Kurdistan Workers Party (PKK), locked in a bloody battle with government forces in the southeast of the country.

President Recep Tayyip Erdogan on Saturday lashed out at the west for backing Syrian Kurdish militia group the PYD in the fight against IS, which Turkey says is linked to the PKK — which the US and EU consider a terrorist group.

“They are appendages of the same body … If you do not see that the PYD is a terror organisation that means that you do not see the Ankara attack as a terror attack,” Erdogan said during a speech in Istanbul.

“The end of this crippled logic is that you don’t see the Brussels and Paris attacks — and god forbid any attacks in London — as terror attacks. Is the fight with terrorism not supposed to be a common struggle?”