Maruti Suzuki(MRTI.NS) has no idea when the Manesar factory hit by a deadly riot this week will reopen, the carmaker's chairman acknowledged on Saturday, saying it was impossible to import extra vehicles or shift lost production to another plant.

India's biggest car company stopped production at a factory in Manesar on Wednesday after a manager was killed and scores injured after a mob of workers attacked officials, smashed equipment and set fire to parts of the plant.

Trade unionists have accused Maruti of anti-union activities at the plant, shut for weeks last year due to labour unrest.

We cannot start production due to a danger to life and safety, Chairman R.C. Bhargava told a news conference in his first public remarks following the violence. We will not endanger our people any further.

How long it will take? 10 days? 15 days? I don't know, Bhargava added. We'll put all our resources to study and help the authorities but ... I cannot say when we will be able to restart the plant.

Maruti officials, addressing reporters, denied press speculation that the company would close the Manesar plant.

The Manesar factory, with a total annual capacity of 550,000 cars -- a third of Maruti's output -- is likely to stay closed for at least two weeks, analysts told Reuters, at a cost to the company of around $15 million a day.

We would be very inefficient if we take six months. We'll request the Haryana government to expedite the investigation, a visibly emotional Bhargava told reporters, referring to the police probe being conducted by the Indian state's authorities.

Maruti, which builds its best-selling Swift hatchback -- the runaway leader in its segment -- at Manesar, will not be able to offset some of the lost production with imports or by increasing productivity at its other factory, Bhargava said.

More than $570 million was wiped off Maruti's market value on Thursday when its shares slid to their biggest one-day drop in two years. Shares of parent Suzuki Motor Corp (7269.T) fell a total of 5.7 percent in trading on Thursday and Friday to their lowest level in three and a half years.

Twenty-four senior managers are still in hospital with injuries, mainly fractures of their arms and legs, of the 96 initially admitted after the riot. No workers were injured during the violence, Maruti's chairman added.

Workers at the plant attacked senior officials with iron rods, wooden sticks and unfinished car parts. Police are investigating the factory's entire 3,000-strong workforce and are seeking to press murder charges.

In my wildest dreams, I never thought that a day would come like this, when our own workers would indulge in this kind of rioting and mob violence... leading to the burning to death of one senior officer, Bhargava, who has been with the company since its inception in 1981, told reporters.

The riot began after an altercation between workers and managers over a disciplinary incident involving a single worker. The factory's workers' union has accused Maruti officials of starting the violence and using hired thugs to beat workers.