The insured loss arising from the explosion in Beirut, Lebanon, will hit multiple lines of insurance and is a reminder of the risks posed by hazardous materials in the supply chain, marine experts say.

The tragedy will also add impetus to rate increases in an already-hardening marine market, several sources say.

While it is too soon to know how much the loss will ultimately cost insurers, marine, property, business interruption, contingent business interruption, hospitality and personal insurance lines will all be impacted, they say.

More than 2,700 tons of ammonium nitrate stored in a warehouse in the port of Beirut was reported as the likely cause of the massive blast last Tuesday that left more than 160 dead, thousands injured, and resulted in widespread property damage.

Lebanon’s government stepped down Monday in the wake of the explosion.

So far, Hannover Re, Munich Re and Liberty Mutual have reported that they expect to see claims from the event.

Citing substantial uncertainty in its estimate, reinsurance broker Guy Carpenter & Co. LLC put the total combined hull, cargo and port facility insured losses at within $250 million in a report Friday.

Ryan O’Connor, New York-based North American regional head for ocean cargo at Allianz Global Corporate & Specialty, a unit of Allianz SE, said the insurer expects “limited impact” based on its initial investigations of its portfolio and accounts.

However, the loss might have an “oversized impact on the hardening of rates” because of insurer concerns on port exposures around the world and in the U.S., Mr. O’Connor said.

The marine market has experienced “large losses” in the past five years due to many different natural catastrophes and other events, said Brad Eldridge, vice president of Falvey Cargo Underwriting, part of Falvey Insurance Group, based in North Kingstown, Rhode Island.

For marine cargo business, this event will “add to that in an already hardened market and will prolong it depending on the final number. Rates will increase,” Mr. Eldridge said.

Much of the port was totally destroyed, grain silos partially collapsed, warehouses totally collapsed and ships were overturned in the blast, Guy Carpenter said in its report.

Damage to the urban area adjacent to the port has also been severe, the reinsurance broker said.

The Beirut explosion is “a reminder” that things can happen in port, and insurers should be aware that port risk and cargo accumulation is still a “major factor,” said Lars Gustafson, New York-based managing director of Arthur J. Gallagher & Co.’s marine practice.

The Tianjin port explosion in 2015, which resulted in a $4 billion loss, was a “true wakeup call” for the industry that caused insurers to factor in “a bigger margin for these catastrophe events,” Mr. Gustafson said.

Tianjin triggered a lot of change and focused insurers on a different way of underwriting, he said, adding that he did not expect the Beirut loss to be as big.

This is not just a shipping or a vessel issue, said Andrew Kinsey, New York-based senior risk consultant, marine for Allianz.

The event is “a reminder that it’s a supply chain issue. All stakeholders have to be engaged in this,” Captain Kinsey said.

Misdeclared and improperly stowed hazardous cargoes are a root cause of fires, he said.

In the case of abandoned vessels, and “now with additional pressures in a COVID-19 environment, we’re going to see more of this,” Captain Kinsey said.

He cited the example of FSO Safer, an abandoned floating storage vessel moored in the Red Sea off Yemen that is laden with more than one million barrels of crude oil that the United Nations has said is at risk of rupturing or exploding.

During second-quarter earnings calls with analysts last week, Hannover Re said it would likely see a “major loss” from the Beirut event, while Munich Re also said it expected large claims.

Liberty Mutual said it would see a loss in the range of $25 million to $50 million, based on initial indications, but that this estimate could change.