The threat came on Saturday as violence in the south of the country left 11 insurgents and three Afghan policemen dead.

The threat to kill Surya Narayan was made by a Taliban spokesman, Yousuf Ahmadi, in a telephone call to AFP.

Narayan was working as a contractor for Afghan mobile phone network Roshan.

It has been decided "that if all Indian companies, engineers and workers in Afghanistan do not get ready to leave the country in the next 24 hours, starting 6pm (1330 GMT) today, we will kill this Indian engineer".

The purported spokesman also said the Taliban leadership had concluded that the Indian engineer was spying for the Americans.

Staying put

Shyam Saran, the Indian foreign secretary, said his government was in touch with the Afghan authorities to establish whether the threat to kill Narayan did indeed came from the people who kidnapped him.

"If all Indian companies, engineers and workers in Afghanistan do not get ready to leave the country in the next 24 hours ... we will kill this Indian engineer"

Yousuf Ahmadi,
purported Taliban spokesman

The foreign ministry said it was sending a team of officials, including hostage negotiators to Kabul to help secure Narayan's release.

But it said India was committed to maintaining a presence in Afghanistan to help its economic development. India has close relations with Afghanistan and is involved in numerous aid and reconstruction projects.

Security is a big worry in Afghanistan with Taliban attacks mounting as Nato prepares to double its peacekeeping operations and the United States hopes to cut its forces there by several thousand.

Violent attacks

Elsewhere, nine Taliban insurgents were killed during fighting that raged overnight on Friday into Saturday, while 12 insurgents, including top commanders, were captured in a joint Afghan-coalition operation in Panjwayi, a western district in the southern Kandahar province, according to Asadullah Khalid, the regional governor.

Also on Saturday morning, about 50 Afghan soldiers and police attacked a Taliban camp hidden in mountains in the district of Kajaki, about 100km north of the Helmand capital of Lashkar Gah, a local Afghan army commander, General Rahmattalluh Roufi, said.

After a one-hour battle, Afghan forces ventured into the mountains and found caves that had been used by the Taliban. The bodies of two slain fighters were found, along with several machine guns.

Taliban insurgents concealed in mountains also fired on a vehicle carrying four policemen late on Friday, killing three of them and wounding the other on a remote road outside the southern Helmand provincial town of Baghran, said police official Haji Rafiq Khan.