* Thirty hostages, at least seven foreign, killed -source
* About 60 foreigners still held or missing on Friday
* Western governments not consulted, Algiers faces questions
* 10 Japanese, 8 Norwegians, "less than 30" Britons at risk
About 60 foreigners were still being held hostage or missing inside a gas plant on Friday after Algerian forces stormed the desert complex to free hundreds of captives taken by Islamist militants, who threatened to attack other energy installations.
The attack, which plunged capitals around the world into cirsis mode, is a serious escalation of unrest in northwestern Africa, where French forces have been in Mali since last week fighting an Islamist takeover of Timbuktu and other towns.
"We are still dealing with a fluid and dangerous situation where a part of the terrorist threat has been eliminated in one part of the site, but there still remains a threat in another part," British Prime Minister David Cameron told his parliament.
A local Algerian source said 60 foreigners were still in the facility and some were being held hostage, but it was unclear how many and how many might be in hiding elsewhere in the sprawling compound. It was also not known whether some might have been killed and the bodies not found.
Those still unaccounted for included 10 from Japan, eight Norwegians and a number of Britons put by Cameron at "less than 30". Washington has said a number of Americans were among the hostages, without giving details, and the local source said a U.S. aircraft landed nearby on Friday.
As Western leaders clamoured for news of their nationals, several expressed anger they had not been consulted by the Algerian government about its decision to storm the facility.
Algeria's state news agency said earlier more than half of 132 foreign hostages were freed and that the army had rescued 650 hostages, 573 of whom were Algerians.
"(The army) is still trying to achieve a 'peaceful outcome' before neutralising the terrorist group that is holed up in the (facility) and freeing a group of hostages that is still being held," it said, quoting a security source.
Thirty hostages, including several Westerners, were killed during Thursday's assault, the source said, along with at least 18 of their captors, who said they had taken the site as retaliation for French intervention against Islamists in neighbouring Mali.