Saudi Arabia has asked its citizens to "immediately" leave Lebanon and advised Saudi nationals not to travel to the country, as tensions between the two nations have risen over the past week.

"The Kingdom advised all citizens not to travel to Lebanon from any other international destinations," Saudi Arabia's Ministry of Foreign Affairs said in a statement reported by Al Arabiya.

Saudi Arabia's advisory comes on the heels of Lebanese Prime Minister Saad Hariri's shock resignation in Riyadh on Saturday. Bahrain had also issued a travel warning against Lebanon in the aftermath of his announcement.

"Due to the current conditions and developments in Lebanon, the foreign ministry asks citizens present in Lebanon to leave immediately and exercise extreme caution," Bahrain's foreign ministry said in a statement.

Saudi Arabia, Bahrain, and other Gulf nations have taken a strong stance against regional rivals Iran and Hezbollah, an Islamist Lebanese political group that is supported by Tehran. Saudi leaders also accused Iran and Hezbollah of collaborating with Yemen's Houthi rebels to launch a missile at Riyadh over the weekend.

"We will treat the government of Lebanon as a government declaring war on Saudi Arabia due to the aggression of Hezbollah," Saudi Minister of Gulf Affairs Thamer al-Sabhan said.

Iran has denied any involvement.

Hariri, who is a dual Saudi and Lebanese national and widely believed to be backed by the Saudi government, in his resignation speech cited fears for his life and called out Hezbollah, which maintains a military wing. He said the group, which has been heavily involved in Syria supporting President Bashar Al Assad, is a destabilizing force within Lebanon.

Hezbollah chief Hassan Nasrallah responded to Hariri's comments claiming Riyadh had "imposed" the decision on the prime minister.

"It is clear that the resignation was a Saudi decision that was imposed on Prime Minister Hariri. It was not his intention, not his wish, and not his decision," Nasrallah claimed, according to Voice of America.

Last year, Hariri brought together a unity cabinet that included Hezbollah ministers.

Hassan Nasrallah and Mohammed bin Salman
Saudi Arabia is opposed to Lebanon's Hezbollah, which is backed by Iran

This isn't the first time Gulf nations have asked their citizens to leave Lebanon.  In 2016, several gulf nations made similar travel advisories, with the UAE banning its citizens from visiting the country.

Saudi Arabia also raised its travel advisory for Lebanon back in 2016, similar to now.