A boy who was wounded after security forces in Indian-administered Kashmir opened fire at a protest over the execution of a separatist died of his injuries Monday, a hospital said.

Ubaid Mushtaq, who doctors say was 12 or 13 years old, died around 3:00am at Srinagar's main hospital after suffering bullet wounds in the protest on Sunday at Watergam, a senior hospital official said on condition of anonymity.

Meanwhile, residents of Kashmir valley chafed for a second day Sunday under a curfew imposed following the hanging of a local separatist which has sparked a fresh debate on capital punishment.

Mohammed Afzal Guru, a Kashmiri Muslim convicted of helping to plot the 2001 attack on the Indian parliament which left 10 people dead, was executed on Saturday in New Delhi's Tihar jail.

Fearing a backlash, Indian authorities imposed an indefinite curfew on Saturday in major populated areas of Kashmir, shut down Internet services and blocked local newspapers in a bid to prevent demonstrations.

One protester died on Sunday when he jumped into the Jhelum river to escape government forces in the Sambal area and another four were injured after police fired tear gas to disperse a crowd near Guru's home town of Sopore, 43 kilometres (27 miles) from the biggest city of Srinagar.

Abdul Hafeez, a resident of Srinagar, said his two-month-old granddaughter needed milk, but they were unable to go shopping because of strict orders restricting people to their homes.

"We have seen so much violence in the past. We just hope that things return to normal as quickly as possible," he told AFP.

Guru was convicted of waging war against India and conspiring with the Islamist militants who attacked parliament -- an event that brought nuclear-armed India and Pakistan to the brink of another conflict.

The one-time fruit merchant and medical college dropout always insisted he was innocent and claimed that he had been denied a proper legal defence. Protesters in Kashmir have often accused the police of framing him.

The world's biggest democracy uses capital punishment for the "rarest of rare" crimes.

It had not carried out an execution since 2004 until the hanging in November last year of Mohammed Kasab, the lone surviving gunman of 2008 militant attacks in Mumbai.

The two executions -- both approved under new President Pranab Mukherjee -- raised concerns among human rights activists who had hoped India was phasing out executions.

"India should end this distressing use of executions as a way to satisfy some public opinion," said Meenakshi Ganguly, South Asia director at Human Rights Watch.

Amnesty International was also quick to condemn Guru's hanging as a "disturbing and regressive trend" towards executions in India.

A section of the Indian press speculated on who could be the next to face the gallows, while the respected left-of-centre newspaper The Hindu slammed the execution.

"There is no principle underpinning the death penalty in India today except vengeance. And vengeance is no principle at all," the daily wrote.

In Kashmir, where a bloody separatist conflict has claimed an estimated 100,000 lives over the last 20 years, some feared that the execution could feed local anti-India feeling and spur more violence.

State chief minister Omar Abdullah said the long-term implications of Guru's hanging were worrying as they were linked to the people of the region.

"Like it or not, the execution has reinforced the point that there is no justice," he told India's NDTV network.

Guru's execution was mired in further controversy on Sunday after his family said they learned about it from television reports. The government said it had sent a letter by registered mail.

"We were not informed by the government... if they sent a letter, please show us the receipt," Yasin Guru, a cousin, told the same news channel.

In Muzaffarabad, the main city in Pakistan-administered Kashmir, around 400 people held special "funeral" prayers for Guru, led by Shahabuddin Madani, the leader of religious party Jamiat Ahle Hadith.

"The execution of Guru has infused a new life in the Kashmiri freedom struggle and people will now fight against Indian forces everywhere, in mountains and planes of Kashmir," Madani warned.