Both Congress and the BJP said the hanging of Guru, a Jaish-e-Mohammed militant, would send a message to terror outfits that India would not tolerate terrorism.
"The law has taken its course. The Parliament attack convict has been hanged," Congress spokesman Rashid Alvi said reacting to the execution of Guru in Tihar Jail here.
"Justice has been done," another Congress spokesman Sandeep Dikshit said.
Questioning the delay in Guru's hanging, BJP said it should have happened much earlier after the confirmation of the capital punishment by the Supreme Court in 2005.
"The capital punishment awarded to Afzal Guru today is a part of legal and judicial process which ought to have taken place much earlier. The attack on the Indian Parliament happened in 2001, that is 12 years ago, which was an attack on India.
"Why this sort of delay inspite of overpowering desire of the people of the country that those who are accused of such a heinous offence ought to be given the capital punishment as affirmed by the highest court of the land. This question would remain important and an answer would have to be found out," BJP Chief Spokesperson Ravi Shankar Prasad told reporters here.
In Chennai, Information and Broadcasting Minister Manish Tewari said the decision to hang Guru was not based on political considerations.
"The process of Article 72 unfolded and once the mercy petition was rejected by the president (Pranab Mukherjee) the law took its own course," Tewari told a press conference.
He was referring to the article of the constitution under which a President can grant pardon or commute the sentence of any convict.
Alvi said the capital punishment to Afzal Guru would send a message to all terror outfits that India will not tolerate terror.
"We have sent a message to the world that we cannot tolerate terrorism at any cost. Anybody committing any acts of terror will be punished. People of our country and government have zero tolerance for terrorism", he said.
Taking a swipe at the BJP, Alvi said terrorists released by the NDA government during the Kandahar plane hijack episode were those who planned attack on Parliament.
BJP spokesman Rajiv Pratap Rudy said: "Though delayed, we still feel that the hanging of Afzal Guru was a right action. This action is delayed. But undoubtedly it is a welcome action."
CPI(M) said the law of the land has taken its course as far as attack on the Indian Parliament is concerned.
"I think, the law of the land with all its provisions has finally been completed as far as the Afzal Guru case and the attack on the Indian Parliament is concerned. The issue which had been lingering for the past 11 years has finally completed its its due course," CPI(M) Polit Bureau member Sitaram Yechury said.
In Srinagar, People's Democratic Party expressed disappointment over Guru's hanging, saying the "sensitivities" of the people of Jammu and Kashmir should have been taken into account before taking the decision.
PDP spokesman Naeem Akhtar also criticised Guru's burial inside the prison complex in New Delhi, saying the body should have been given to his family in Kashmir.
The All Party Hurriyat Conference announced a four-day mourning on the death of Guru.
"We call on people to observe four-day mourning on the hanging of Guru. A complete shutdown will be observed over the mourning period," Hurriyat Conference spokesman Shahidul Islam told PTI in Srinagar.
Shiv Sena, another party strident in its demand for Guru's execution, welcomed his hanging, saying the government showed "courage" in taking this decision.
"The government showed courage in hanging Guru," Shiv Sena spokesperson Sanjay Raut said in Mumbai but rued the delay in the process.
Raut said when Pranab Mukherjee had met Shiv Sena chief late Bal Thackeray during his campaign for the Presidential elections, the Sena supremo had urged him not to grant clemency to Guru.
RSS welcomes execution of Afzal Guru
RSS today welcomed the execution of Parliament attack convict Afzal Guru though it came after some delay and insisted that all Indians should rise above their differences to oppose terrorism unitedly.
"We welcome the implementation, albeit after a delay, of the Supreme Court order to hang Afzal Guru, the principal conspirator of the Parliament House attack of 2001. The Central government should have taken this decision earlier," RSS All-India propaganda chief Manmohan Vaidya said in a statement.
The RSS founthead has often criticised the Congress-led UPA government in the past for delaying the hanging of Guru despite the Supreme Court upholding the death sentence.
"In future also, all Indians should rise above partisan politics and unitedly fight against terrorism," Vaidya said.
RSS leader Ram Madhav also welcomed Guru's hanging.
"Guru had challenged the sovereign power of India by attacking our Parliament. He deserved to be shown that power," Madhav said.
BJP welcomes Afzal Guru's execution
BJP today welcomed the execution of Parliament attack convict Mohammed Afzal Guru, saying it was a "much awaited and much wanted decision".
"This action is delayed. But undoubtedly it is a welcome action. ...it was a much awaited decision, much wanted decision so that the world could see that India is committed against terror, the fight against terror," BJP spokesman Rajiv Pratap Rudy told reporters here.
He said the BJP has always been pressing for strong and prompt action against perpetrators of terror.
"Any action against terror like the hanging of Afzal Guru should be immediate. It cannot be delayed. If the highest court of the land upheld the conviction of Afzal Guru in 2007, thereafter there was no reason that any mercy petition should have been delayed for so long," he said.
"Though delayed, we still feel that the hanging of Afzal Guru was a right action. It has been done and the people of this country have been wanting and waiting for it for a long time," he said.
Days after his mercy petition was rejected by the President, Guru was hanged at 8 AM at Tihar jail here.
Guru was convicted of conspiracy in the December 2001 attack on Parliament and was sentenced to death by the Supreme Court in 2004.
On December 13, 2001, five heavily-armed gunmen stormed the Parliament complex and opened indiscriminate fire, killing nine persons.