A message from the warden on the US Embassy website says: "There are increased indications that terrorists are planning imminent attacks in New Delhi.

"Terrorists have targeted places in the past that US citizens or westerners are known to visit.

"Markets, such as those located in Chandni Chowk, Connaught Place, Greater Kailash, Karol Bagh, Mehrauli and Sarojini Nagar can be attractive targets for terrorist groups.

"If you are in an area where unattended packages are spotted, you should immediately exit the area and report the packages to authorities."

The US had issued a similar message last month.

But the latest message has the word "imminent" added to it.

The warnings come as India has been battling to assure the world it can serve as a safe host for the Commonwealth Games. 

The last major attack in New Delhi was a series of bomb blasts that ripped through busy, upmarket shopping areas in September 2008, leaving 22 people dead and wounding 100 more.

Security concerns about the Commonwealth Games, which are due to open on October 3, were stoked last month when two low-intensity bombs went off at a cricket stadium in the southern city of Bangalore ahead of an Indian Premier League match.

Some 8,000 athletes are expected to attend the Commonwealth Games.

India has promised to provide "foolproof" security for athletes and spectators during the Games.

In its advisory, the British Foreign and Commonwealth Office warned: "At this time, there are increased indications that terrorists are planning attacks in New Delhi.

"You should be particularly conscious of security considerations in the vicinity of key Government installations and tourist sites."

The advisory from Australian Foreign Office said: "Reliable reporting indicates that terrorists may be planning to attack markets in New Delhi, including those frequented by foreigners.

"Specific and credible information indicates terrorist attacks in New Delhi, especially in markets, may be imminent."

New Zealand officials said: "New Zealanders are strongly advised to avoid market areas of New Delhi in coming days and weeks."

The Delhi Police has issued a statement saying it is aware of the warnings.

Spokesman Rajan Bhagat said: "We appeal to the public to be vigilant and fully cooperate with the Delhi Police.

"We are taking appropriate measures."

In February, a bomb exploded in a packed restaurant popular with travellers in the western Indian city of Pune, killing 16 people, including five foreigners.

It marked the first major incident since the 2008 Mumbai attacks in which 10 Islamist gunmen launched an assault on multiple targets in India's financial capital, killing 166 people.

India blamed the Mumbai attacks on the banned Pakistan-based Islamist group Lashkar-e-Taiba, straining already tense diplomatic ties with its neighbour.

The run-up to the hockey World Cup in February and March was overshadowed by concern some teams might pull out.

Ultimately, the tournament went ahead without incident with a heavy police presence.


Related stories
April 2010: New Zealand netball players fear for safety at Commonwealth Games
April 2010: New concerns over Commonwealth Games security after bomb blasts
April 2010: India promises to tighten security before Commonwealth Games after bomb attack
April 2010: Commonwealth Games in Delhi will be wonderful predicts Hooper
March 2010: Confidence in Delhi security growing claims CGF chief