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.

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.

Saudi Arabia's Ministry of Labor and Development is intensifying its crackdown on expats working in jobs limited to Saudi nationals. 

In an announcement made on its official Twitter account on Wednesday, the ministry said it's currently arresting expats caught working in nationalized sectors, including telecom and retail.  

"The Ministry will not tolerate expats illegally working in the telecom sector or any other industry which has been nationalized. We are currently arresting violators and referring them to authorities, who will later deport them," the statement read. 

The Ministry's latest campaign comes at a time when the kingdom is working on reducing unemployment rates among nationals. 

It also comes less than a month after authorities announced the country would be reducing the validity of expat work visas for private sector employees from two years to one.

"The ministry will ensure that there are inspectors across all telecom malls and companies. We also call on citizens to report violators by phone or through our mobile app: #Together_tomonitor."

"An excellent decision, especially when it comes to shopping outlets in Jeddah."

"How do I report someone?"

"Whether you allow it or not, the reality is they're working and violating [leaders] words and order." 

"Expats are vital to some sectors, at least until our youth are trained to take on such jobs." 

Official figures reveal that close to 9 million foreigners are employed in the kingdom. 

However, these numbers were released before the country intensified efforts to reduce its reliance on foreign labor and boost employment opportunities for Saudi nationals under the kingdom's Vision 2030. 

The ambitious blueprint aims to fight unemployment, which continues to rise at alarming rates among Saudi nationals. 

The kingdom has passed several orders under the plan, including one that terminates all contracts pertaining to expatriate workers in governments and ministries within three years and another that nationalizes jobs in shopping malls. 

The ever-transforming Vision 2030 also aims to develop non-oil industries, support small and medium enterprises, increase the participation of Saudi women in the workforce and create a broader investment base in the country.