New York: United Nations Secretary-General Antonio Guterres said that he is "deeply concerned" about the exchange of military strikes between Iran and Pakistan. He called on both nations to exercise maximum restraint to avoid a further escalation of tensions.

According to a statement released by UN Chief Stephane Dujarric, Antonio Guterres said, "The Secretary-General is deeply concerned about the recent exchange of military strikes between Iran and Pakistan, which have reportedly caused casualties on both sides."

"He urges both countries to exercise maximum restraint to avoid a further escalation of tensions," he added.

Antonio Guterres underlined that all security concerns between Iran and Pakistan must be addressed by "peaceful means" through dialogue and cooperation, in accordance with the principles of sovereignty, territorial integrity, and good neighbourly relations.

Pakistan said on Thursday that it has launched missile strikes into Iran and that "a number of terrorists were killed during the intelligence-based operation," codenamed "Marg Bar Sarmachar." Pakistan's military action comes after it condemned Tuesday's strike by Iran, which it said killed two children and injured three girls.

In a statement, Pakistan's Ministry of Foreign Affairs (MoFA) said that it had undertaken a series of "highly coordinated and specifically targeted precision military strikes against terrorist hideouts" in the Siestan-o-Baluchistan province of Iran.

"A number of terrorists were killed during the intelligence-based operation codenamed "Marg Bar Sarmachar," it said.

The Pakistan Foreign Ministry said that in its engagements with Iran over the last several years, Pakistan has consistently shared its serious concerns about the safe havens and sanctuaries enjoyed by Pakistani-origin terrorists who called themselves "Sarmachars" on the ungoverned spaces inside Iran. Pakistan said it also shared multiple dossiers with concrete evidence of the presence and activities of these terrorists.

"However, because of a lack of action on our serious concerns, these so-called Sarmachars continued to spill the blood of innocent Pakistanis with impunity. This morning's action was taken in light of credible intelligence of impending large-scale terrorist activities by these so-called Sarmachars," Pakistan's Foreign Ministry stated.

The Iranian Ministry of Foreign Affairs has condemned Pakistan's drone attack on non-Iranian villagers on the border of the two nations, calling it "unbalanced and unacceptable."

It said Iran adheres to the policy of "good neighbourliness and brotherhood" between two nations and does not allow enemies to strain the ties between Tehran and Islamabad.

"The Ministry of Foreign Affairs of the Islamic Republic of Iran condemns Pakistan's unbalanced and unacceptable drone attack on non-Iranian villagers on the border of the two countries," the Iranian Ministry of Foreign Affairs said in a statement.

"At the same time, the Islamic Republic of Iran adheres to the policy of good neighbourliness and brotherhood between the two nations and the two governments of the Islamic Republic of Iran and Pakistan. It does not allow enemies to strain the amicable and brotherly relations of Tehran and Islamabad," it added.

On Tuesday, Iran attacked the headquarters of a terrorist group opposed to Tehran with drones and missiles in Pakistan, Al Arabiya News reported citing Tasnim news agency. Two "important headquarters" of Jaish al-Adl (Army of Justice) in Pakistan were "destroyed," Al Arabiya News reported citing Tasnim News Agency.

The strikes were concentrated in an area in Pakistan's Balochistan where "one of the largest headquarters" of Jaish al-Adl was located, the report said.

Formed in 2012, Jaish al-Adl, designated as a "terrorist" organization by Iran, is a Sunni terrorist group that operates in Iran's southeastern province of Sistan-Baluchistan, Al Arabiya News reported.

Over the years, Jaish al-Adl has launched numerous attacks on Iranian security forces, Al Arabiya News reported. In December, Jaish al-Adl took responsibility for an attack on a police station in Sistan-Balochistan that claimed the lives of at least 11 police personnel.

Iran's strikes in Pakistan came after Iran's Islamic Revolutionary Guard Corps (IRGC) launched missiles into Iraq's Kurdistan region at what it called an Israeli "spy headquarters" and at alleged ISIS-linked targets in Syria, the report said.