Iran has fired a series of ballistic missiles at two military bases in Iraq housing American troops in retaliation for the U.S. killing of top Iranian General Qassem Soleimani last week.

U.S. officials say there have been no reports of any American casualties from the attack but an assessment of the impact of the strikes is still underway.

Iraq’s joint military command said there were no casualties among Iraqi military forces.

The Iraqi military said 22 missiles were fired and struck coalition bases.

United States President Donald Trump later tweeted, “All is well! Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties & damages taking place now. So far, so good! We have the most powerful and well equipped military anywhere in the world, by far!

Trump is expected to speak to media Wednesday morning.

The attack is a major escalation in tension between the U.S. and Iran, and has prompted a flood of worries that the countries may go to war.

Shortly after the attack, Iran’s Foreign Minister, Javad Zarik, said the country does not seek escalation or war, but will defend itself against any aggression.

Canadians are being advised to avoid any non-essential travel to Iran due to the volatile security situation, the regional threat of terrorism and the risk of arbitrary detention.

According to a travel advisory on the Government of Canada website, Canadians, particularly dual Canadian-Iranian citizens, are at risk of being arbitrarily questioned, arrested and detained. Iran does not recognize dual nationality and Canada will not be granted consular access to dual Canadian-Iranian citizens. Canadian-Iranian dual citizens should carefully consider the risks of travelling to Iran.