LONDON: Nations with hostages in Algeria have reacted with muted anger to the North African country's decision to launch a military rescue mission without consultation.

Privately, diplomats are furious and frustrated, but experts said Friday that their scope to react is limited by Algeria's importance as an anti-terrorist ally and major oil and gas producer

Algerian special forces stormed a gas plant in eastern Algeria on Thursday to wipe out Islamist militants and free hostages from at least 10 countries. Several hostages and their captors were reported dead or injured, though numbers remained unclear.

The United States, Britain and other countries said they were not told in advance of the raid, which continued Friday.

Japan summoned the Algerian ambassador for a dressing-down, and Britain said Prime Minister David Cameron had urged his Algerian counterpart to act with caution.

Cameron said Friday that in several calls to Algerian premier Abdelmalek Sellal during the crisis, "I urged that we and other countries affected should be consulted before any action was taken" and offered "U.K. technical and intelligence support - including from experts in hostage negotiation and rescue."

The United States also offered hostage rescue teams, according to a senior U.S. military official, but the offer was refused.

Experts said it was no surprise that battle-hardened Algeria - which threw off French rule in 1962 after years of war, and where some 20,000 people died in a 1990s conflict between the government and Islamist rebels - had decided to go it alone.

"The Algerians are very, very prickly about their sovereignty," said Nigel Inkster, a former senior British intelligence official and terrorism expert with the Chatham House international affairs think tank. "I don't think they were remotely inclined to consider or accept any of the advice or capabilities that were on offer."

There's not much governments can do, however annoyed they are. Algeria is vital to Western hopes of containing Al-Qaeda influence in North and West Africa. Its large oil and gas reserves are crucial both to its own economy and to global energy supply.

Cameron was careful to say Friday that Britain would "stand with the Algerians in their fight against these terrorist forces."

His spokesman, Jean-Christophe Gray, stressed that "this is Algerian sovereign territory and they of course have the right to do as they see fit."

"We have made clear we stand ready to offer assistance and they have not accepted it," Gray said.

The attack is a worrying new development in an unstable region. Militants have in the past kidnapped foreign tourists across North and West Africa, but diplomats said a large and sophisticated attack on a major energy installation marked a departure.

"There are many, many oil and gas installations in the Algerian desert and I am not aware of any serious occurrences previously for years," said Graham Hand, a former British ambassador to Algeria.

Inkster said governments "are going to have to think long and hard" about how to respond to the attack, and to Algeria's lack of coordination with other nations.

"They need to maintain a decent relationship with Algeria for economic reasons, as well as for security and geopolitical reasons," he said.