SRINAGAR, India: A boy shot by security forces in Indian Kashmir died in hospital Monday, taking the death toll to three during protests at the weekend execution of a local separatist.

Mohammed Afzal Guru, a Kashmiri Muslim hanged on Saturday after being convicted over a deadly raid on the Indian parliament in 2001, is seen by many in Kashmir as having been framed by police for the crime.

His death has led to severe criticism of the government, which failed to inform his family before the execution, and sparked a new debate about India's renewed use of the death penalty after an eight-year informal moratorium.

Fearing a backlash in Kashmir, where anti-India feelings run deep after more than two decades of separatist fighting, authorities have imposed a curfew, arrested local politicians and restricted the local press and Internet.

Crowds of mostly young men have defied the orders. A boy called Ubaid Mushtaq, who doctors say was aged 12 or 13, died in hospital in the early hours of Monday after being shot in the village of Watergam.

A police source said around 3,500 people had attended Ubaid's funeral Monday in Watergam near Guru's home town of Sopore.

Two other men died on Sunday after they drowned trying to escape police during a demonstration in the village of Sumbal, about 25 kilometres (15 miles) north of the main city of Srinagar.

The handling of Guru's execution has been severely criticised by Kashmir's Chief Minister Omar Abdullah, who said it would deepen the sense of frustration and alienation in India's only Muslim-majority state.

Pakistan, which runs part of the divided Himalayan region which has sparked two wars between the neighbours, also criticised India's hardline security measures.

"We... express our serious concern on the high-handed measures taken by India in the wake of Afzal Guru's execution," a foreign ministry spokesman said.

Guru's family slammed the Indian government for failing to inform them in time, meaning no final meetings could be arranged between him, his wife and his teenage son.

A letter sent from the government announcing that his mercy plea had been rejected arrived only on Monday morning.

"It is shocking that the government delivered a letter to us two days after they executed Afzal," Yasin Guru, a cousin of the dead man, told AFP by phone.

Indian Home Minister Sushil Kumar Shinde defended the decision at a press conference on Monday, saying a letter had been sent on Thursday but that the execution had to be handled with secrecy.

"The government had to be very careful on this. We have to maintain secrecy and we had to take a quick decision," he said.

Chief Minister Abdullah, usually a government ally, has been strongly critical of the manner in which Guru was executed and its impact in highly militarised Kashmir, where simmering anger leads to regular deadly street protests.

"I find it very hard to reconcile myself to the fact that we executed a person who wasn't given the opportunity to see his family for the last time," Abdullah told an Indian news channel on Sunday.

The number of police on the streets was increased on Monday amid fears of protests on the 29th anniversary of the execution of a separatist leader.

The February 11 anniversary of the death of Maqbool Bhat, a founder of the Jammu Kashmir Liberation Front, is usually marked by large rallies and separatist groups called for a general strike on Monday.

Some of the few people authorised to leave curfew-bound areas on Monday were tourists who headed to the airport after being confined to their hotels over the weekend.

Guru's execution has also sparked protests on the Pakistani side of Kashmir.

Around 1,500 activists from jihadi groups and political parties, including the main ruling Pakistan People's Party, took part in the demonstration, police said.