LONDON (AP) ― Ships sailing under Britain’s flag will be permitted to carry armed guards on some perilous routes to combat the threat from pirates, the prime minister said Sunday.

David Cameron said Britain was reversing its opposition to the use of weapons aboard ships, amid mounting concern about the risks of vessels and crew being seized by pirates ― particularly off Somalia’s coast.

Cameron’s office said the use of weapons on British-flagged ships is banned under firearms laws, but that new rules would be in place within a month.

Britain’s announcement follows the decision in February of the International Chamber of Shipping, the major trade association of ship owners, to support members hiring private security companies to provide protection.

“The evidence is that ships with armed guards don’t get attacked, don’t get taken for hostage or for ransom, and so we think this is a very important step forward,” Cameron told BBC television during a visit to a Commonwealth summit in Australia, where he discussed the issue with leaders from the Seychelles and Mauritius.

Cameron said Britain’s interior ministry would issue licenses authorizing the use of armed guards for ships operating off East Africa’s coast, in other parts of the Indian Ocean and in the Arabian Sea.

He said the change is intended for commercial vessels, rather than leisure sailors ― such as Paul and Rachel Chandler, the British couple held for 388 days by Somali pirates.

“The extent of the hijack and ransom of ships around the Horn of Africa I think is a complete stain on our world,” Cameron told the BBC. “The fact that a bunch of pirates in Somalia are managing to hold to ransom the rest of the world and our trading system I think is a complete insult.”

Many nations, including Britain and Germany, had previously been nervy over the use of armed guards ― and Cameron did not elaborate on what rules would apply on the use of lethal force by private security contractors.

“Piracy is a very serious problem and it’s sensible to allow ships to take the appropriate measures to protect their crew and cargo,” Britain’s Transport Secretary Justine Greening said in a statement. “The U.K. will allow the use of private armed security guards on our ships in exceptional circumstances and where it is lawful to do so.”

In Germany, ship owners have pressured lawmakers to change the nation’s weapons law to allow German ships to carry armed guards.

Under current laws, the captains are required to apply individually for the right to carry arms, but would only be able to use them under certain, restrictive circumstances.

Lawmakers are debating how legislation could be changed to allow for ships to routinely carry weapons, plans which are being met with resistance from some opposition lawmakers and representatives of Germany’s powerful police force, which worries such changes could lead to an overall easing of the nation’s strict weapons laws.

The U.N. International Maritime Organization issued guidance in May on the use of armed guards ― warning that there had been 489 acts of piracy or armed robbery against ships in 2010, an increase on the previous year.

Some maritime groups and insurers have opposed arming ships because of liability issues, and over fears that to do so could provoke an arms race with pirates. Other skeptics have worried that if ships from wealthy companies hire expensive security crews, hostage-takers will simply switch focus to softer targets.

Earlier this month, the International Chamber of Shipping urged nations to also take additional military action to combat piracy.

“Private armed guards do not represent a long-term solution,” the organization’s chairman Spyros Polemis said. “Rather, their use actually signifies a failure on the part of the international community ― and those governments with significant military forces ― to ensure the security of maritime trade.

“Governments don’t like it when we say this, but the reality is that they have ceded control of the Indian Ocean to the pirates,” he said.

Figures released earlier this month by the EU Naval Force show that pirates hold nine ships and an estimated 246 hostages. In February, pirates killed a Filipino crewman aboard the German-owned MV Beluga Nomination.