Riot police fired water cannon Wednesday at a protest in New Delhi over the gang-rape of a 23-year-old student, as leader of India's ruling party Sonia Gandhi swelled a wave of anger over the attack.

During the protest screened live on television, police could be seen hosing down demonstrators after a group of them tried to tear down steel barricades outside the official residence of New Delhi's Chief Minister Sheila Dikshit.

British Foreign Secretary William Hague on Thursday urged Syrian opposition groups to unite to halt extremists gaining influence in the country, as new leaders for the movement were elected in Doha.

Hague, speaking during a visit to India, said that opposition factions had to work together to end the conflict in Syria which erupted last year when protesters took to the streets to demand the fall of President Bashar Assad.

The United States embassy in New Delhi was shut on Friday and employees were asked to stay on the compound due to the risk of protests over an anti-Islam film, embassy sources said.

The decision to close the embassy was taken by authorities to prevent any "untoward incident" near the highly guarded premises in the diplomatic quarter of the capital, an official told Agence France Presse, requesting anonymity.

Indian police have concluded that members of Iran's Revolutionary Guards, a branch of the Iranian military, carried out an attack on an Israeli diplomat in New Delhi in February, a report said on Monday.

The Times of India, citing the police investigation, said that five suspects were believed to have worked with a local Indian journalist to plan the attack which saw a hitman on a motorbike attach a magnetic bomb to an embassy car.

U.S. Defense Secretary Leon Panetta arrived in India on Tuesday for talks focusing on Washington's strategic shift towards Asia, as the United States eyes New Delhi as a potentially pivotal partner.

Security ties with India have steadily improved in recent years but U.S. officials have yet to realize the goal of a game-changing alliance that could check China's role and empower the two countries' economies, analysts say.

A simple, cheap dose of zinc helps the recovery of newborns suffering from bacterial infections such as pneumonia and meningitis, according to an Indian study reported on Thursday in The Lancet.

Doctors gave 10-milligram daily supplements of zinc to 332 babies who were being given antibiotic treatment at hospitals in New Delhi, and compared the outcome against 323 infants who were given a placebo as well as antibiotics.

President Asif Ali Zardari will on Sunday become the first Pakistani head of state since 2005 to visit arch-rival India when he makes a trip that includes lunch with Prime Minister Manmohan Singh.

Interpol has issued "red notices" for four Iranians suspected of involvement in a bomb attack near the Israeli embassy in New Delhi, the international police agency said Thursday.

Indian authorities requested the notices, which instruct police across the globe to arrest the suspects, following the February 13 embassy attack that left an Israeli diplomat seriously injured.

Indian police said Friday that Interpol "red corner" notices were being drawn up for three men of Iranian origin identified as suspects in an attack on an Israeli diplomat in New Delhi.

Delhi police commissioner Brijesh Kumar Gupta also revealed that investigations had established a clear link between the February 13 attack and a similar plot targeting Israeli diplomats in Bangkok.

New Delhi police said Wednesday they had arrested a man in connection with last month's bomb attack on an Israeli diplomat's car, which Israel blamed on Iran.

Police spokesman Rajan Bhagat said the man was 50-years-old but gave no details as to the charges he faced related to the February 13 attack.