Pakistan's capital was under strict security lockdown as Chinese Premier Li Qiang landed in the city on Monday ahead of a heads-of-government gathering of the Shanghai Cooperation Organisation this week, Reuters reported.

Li's visit is the first by a Chinese premier to Pakistan in 11 years, Pakistan's Prime Minister's Office said. Pakistan's Prime Minister Shehbaz Sharif received Li at the airport.

The government has announced a three-day public holiday in Islamabad, with schools and businesses shut and large contingents of police and paramilitary forces deployed.

Pakistan army troops will be responsible for the security of the capital's Red Zone, the location of the parliament and a diplomatic enclave and where most of the meetings will take place, according to the interior ministry.

The threat alert has been high in the South Asian nation ahead of the SCO summit, especially after the killing of two Chinese engineers and shooting to death of 21 miners, read the report.

Tensions have mounted after jailed former Prime Minister Imran Khan called for a protest on Oct. 15 to press for his release and agitate against the coalition government, following violent clashes between his party loyalists and security forces.

Islamabad has sought to curb all movement of Chinese nationals in the city, citing fears they could be targets for violence from separatist militants.

The 23rd meeting of the SCO, which comprises nine full members including China, India, Iran and Russia, is scheduled for Tuesday and Wednesday in Islamabad.

As well as attending the SCO summit, Prime Minister Li is also undertaking a four-day bilateral visit to Pakistan from Monday to Thursday, accompanied by senior officials, Pakistan's foreign office said.

Li and Pakistani Prime Minister Shehbaz Sharif will lead their respective delegations to discuss economic and trade ties and cooperation under the China Pakistan Economic Corridor (CPEC), a $65 billion investment in the South Asian country under Chinese President Xi Jinping's Belt and Road Initiative.

Li will also inaugurate the CPEC funded Gwadar International Airport in restive southwestern Balochistan province, which borders Afghanistan and Iran, Pakistan's prime minister's office said.

The SCO participants will be represented by the prime ministers of China, Russia, Belarus, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan as well as the first vice president of Iran and external affairs minister of India, the foreign office said.

US officials believe Israel has narrowed down targets in its potential response to Iran's attack this month to military and energy infrastructure, NBC reported on Saturday.

The Middle East remains on high alert for further escalation in a year of war as Israel battles Iran-backed groups Hezbollah in Lebanon and Hamas in Gaza, Reuters reported.

Israel has repeatedly said it will respond to Iran's October 1 missile barrage, which was launched in retaliation for Israel's military operations in Gaza and Lebanon and the killings of a string of Hamas and Hezbollah leaders.

There is no indication that Israel will target nuclear facilities or carry out assassinations, the NBC report said, citing unnamed US officials and adding that Israel has not made final decisions about how and when to act.

US and Israeli officials said a response could come during the current Yom Kippur holiday, according to the report.

The conflict between Israel and Hezbollah militants erupted a year ago when Hezbollah began launching rockets at northern Israel at the start of the Gaza war, and has sharply escalated in recent weeks.

Reuters reported that Hezbollah said on Sunday it was fighting Israeli forces trying to infiltrate Ramya village in southern Lebanon.

Israel's military said it continues to operate in southern Lebanon to dismantle "terrorist infrastructure".

"Over the past day, the IAF (air force) has struck approximately 200 Hezbollah targets deep in Lebanon and southern Lebanon, including terrorist cells, launchers, anti-tank missile posts, and terrorist infrastructure sites," it said.

Israel also said five launches that crossed from Lebanon were intercepted by the air force.

The United States expanded sanctions against Iran's petroleum and petrochemical sectors on Friday in response to an Iranian missile attack on Israel, the administration of President Joe Biden said.

The U.S. move adds petroleum and petrochemicals to an executive order that targets key sectors of Iran's economy with the aim of denying the government funds to support its nuclear and missile programs, Reuters reported.

"The new designations today also include measures against the 'Ghost Fleet' that carries Iran’s illicit oil to buyers around the world," Jake Sullivan, the national security adviser, said in a statement. "These measures will help further deny Iran financial resources used to support its missile programs and provide support for terrorist groups that threaten the United States, its allies, and partners."

Israel is vowing to respond to Iran's Oct. 1 missile attack, launched in retaliation for Israeli strikes in Lebanon and Gaza and the killing of a Hamas leader in Iran.

The U.S. Treasury can now "impose sanctions on any person determined to operate in the petroleum and petrochemical sectors of the Iranian economy," it said in a statement.

Biden has said Israel should seek alternatives to attacking Iran's oil fields. Gulf states are lobbying Washington to stop Israel from attacking oil sites because they are concerned their own facilities could come under fire from Tehran's proxies if the conflict escalates, three Gulf sources told Reuters.

The Treasury Department also said it was designating 16 entities and identifying 17 vessels as blocked property, citing their involvement in shipments of petroleum and petrochemical products in support of the National Iranian Oil Company.

Concurrently, the State Department took steps to disrupt the money flow into Iran's weapons programs and support for "terrorist proxies and partners."

It imposed sanctions on six entities involved in Tehran's petroleum trade and identified six ships as blocked property.

Iran's oil exports have risen under Biden's tenure as Iran succeeds in evading sanctions and as China has become Iran's major oil buyer.

The Eurasia Group risk consultancy said on Friday the U.S. could cut Iran's oil exports through tighter enforcement of previously imposed sanctions, for instance through satellite imaging for stricter monitoring of tankers that have turned off transponders.

The U.S. could also pressure countries to support enforcement efforts such as Malaysia, Singapore and the United Arab Emirates, it said. But that approach "would require strong diplomatic pressure on two partners, Malaysia and UAE, which are both reluctant to support efforts favoring Israel," it said. Tougher enforcement of sanctions would likely require targeting Chinese firms shipping Iranian crude, it said, as China buys nearly 90% of Iran's crude-oil exports.