Rescue workers carry the coffin of one of the hostages killed during a hostage crisis in a gas plant at the hospital in In Amenas January 21, 2013. The hostage death toll from a four-day siege at an Algerian gas plant deep in the Sahara has risen to almost 60, with at least nine Japanese nationals also reported killed in an attack claimed by a veteran Islamist fighter on behalf of al Qaeda.

It is not yet known when the Algerian In Amenas gas complex will restart after a bloody siege by Islamist fighters there ended on Sunday, operators BP and Statoil said on Monday.

The field produces 9 billion cubic metres (bcm) of gas per year, equal to around 11 percent of Algeria's yearly gas production. The North African country is an important gas supplier to Europe, most notably Italy and Spain which it supplies via subsea pipelines.

Algeria's Oil Minister said during a visit to the site on Sunday the plant could restart within two days as damage to the installation was not very significant.

However, a spokesman for BP said the company, which owns 46 percent of the In Amenas joint venture, had no information about the state of the site.

“There's no guidance on start up,” he said, a comment also given by a Statoil spokesman.

Gas exports from Algeria to Italy were above their 30-day average on Monday, the Italian grid operator said, and traders added Algerian gas flows to Spain were normal.

Algeria exported 34.4 bcm of gas in 2011, more than 60 percent of which was sent to Italy via pipelines, according to BP statistics.

The In Amenas site is located around 1,300 kilometres from the capital Algiers and is jointly owned by BP, Statoil and Algeria's national oil and gas company Sonatrach.

Sonatrach estimates it is losing around $11 million a day due to the shutdown of the In Amenas plant, a company source said.

The death toll from the siege reached at least 80 after troops stormed the complex to end the hostage crisis and the raid has exposed the vulnerability of multinational-run oil and gas installations in an important producing region. - Reuters