ISLAMABAD - Pakistan strongly condemns an Israeli missile strike that hit the consulate building within the compound of the Iranian embassy in the Syrian capital, Damascus, the Pakistani Foreign Ministry said on Tuesday.

"The attack is an unacceptable violation of the sovereignty of Syria and undermines its stability and security," the ministry said in a statement, adding that "it is a violation of international law and the United Nations' Charter."

At least five people, including a senior Iranian commander, were killed on Monday afternoon in the strike which leveled the building to the ground, leaving an unknown number of casualties, according to the Iranian ambassador to Syria and other sources along with Xinhua reporters on the scene.

Reporters saw thick plumes of smoke rising from the building located on the Mazzeh Highway to the west of Damascus after the attack, which triggered a big boom sound as the Syrian air defenses attempted to intercept the missiles.

"We offer our deepest condolences to the families of the victims and the people and the government of Iran," said the statement.

Attacks against diplomats or diplomatic facilities are also illegal under the Vienna Convention on Diplomatic Relations of 1961, it added.

The irresponsible act of the Israeli forces is a major escalation in an already volatile region, the statement said.

"We call on the UN Security Council to prevent Israel from its adventurism in the region and its illegal acts attacking its neighbors and targeting foreign diplomatic facilities," according to the ministry.