Photo: BP

The scene of the hostage crisis, a natural gas facility in Amenas, Algeria.

Algiers — Algerian troops have ended a siege at a gas facility in the Sahara desert killing 11 Islamist militants after they killed seven hostages, Algerian state news agency APS said. The hostages were summarily killed as the troops tried to free them, it said.

The number of foreign hostages is still unknown four days into the crisis. State media said Friday that 30 or more foreigners were unaccounted for.

Survivors who've made their way to freedom have described harrowing escapes from the terror group. Some invented disguises, others sneaked to safety with locals, and at least one ran for his life with plastic explosives strapped around his neck.

APS has previously said 12 Algerian and foreign workers have been killed since rescue efforts began.

Earlier, 573 Algerians and about 100 of 132 foreigners working at the plant were freed, Algeria said.

Shortly before reports of the final assault emerged, the leader of the hostage-takers, Abdul Rahman al-Nigeri, said the government had to choose between negotiating with the kidnappers and leaving the hostages to die.