ISLAMABAD, Pakistan – President Pervez Musharraf announced Wednesday that Scotland Yard will help investigate the assassination of Benazir Bhutto, reversing his initial rejection of foreign help after he came under pressure to allow a U.N. probe.

Authorities also pushed back parliamentary elections until Feb. 18 – a six-week delay prompted by the rioting that followed the opposition leader’s death. Opposition parties condemned the delay but still plan to take part in the elections, seen as a key step in bringing democracy to Pakistan after years of military rule.

Both developments could ease the turmoil that has gripped Pakistan since Bhutto’s slaying in a gun and suicide bomb attack Thursday, which plunged the nation deeper into political crisis as it struggles to contain an explosion of Islamic militant violence.

The government declared just one day after the attack on Bhutto that an al-Qaida-linked militant orchestrated the killing and aired video footage. But the hasty accusation only served to cast doubt over the government’s account of exactly how she died.

The government has also come under sharp criticism for its security arrangements for Bhutto, who had claimed elements in the ruling party were trying to kill her.

In a nationally televised address Wednesday, a solemn-faced Musharraf said the death of Bhutto, a two-time prime minister, was a great tragedy for Pakistan. He blamed “terrorists” for her assassination and appealed for public unity to combat them.

“This is a time for reconciliation and not for confrontation,” he said.

The government initially said it did not need foreign help to probe the killing. But then Musharraf sought assistance from British Prime Minister Gordon Brown. His reversal could ease pressure for an independent, international investigation into both how she died and whether the government covered it up.

Scotland Yard said it was sending a small team of officers from the Metropolitan Police’s Counterterrorism Command. British Foreign Secretary David Miliband said the team would leave Britain by the end of the week.

The White House said it supported Scotland Yard’s involvement, adding that a United Nations investigation into Bhutto’s slaying was not necessary now.

“Scotland Yard being in the lead in this investigation is appropriate and necessary and I don’t see – we don’t see a need for an investigation beyond that at this time,” presidential spokeswoman Dana Perino said.

State Department spokesman Sean McCormack reiterated U.S. offers to assist in the inquiry. The White House would not comment on why Musharraf had rejected the U.S. offer to help.

“What’s most important is that they proceed quickly and in a transparent and comprehensive way, so that the people of Pakistan can get the answers that they deserve, and that, as they move forward toward the elections with the date certain that was just set today, the people will be able to participate in a process freely,” Perino said.

Ross Feinstein, spokesman for the director of U.S. national intelligence, said his agency has yet to reach any conclusions over who was responsible for the killing.

Asif Ali Zardari, Bhutto’s husband and now chief of her party, reacted to Musharraf’s speech by saying British involvement came too late and should have been sought immediately after a previous assassination attempt against Bhutto in October.

He demanded a U.N. committee investigate her killing, similar to the probe of the 2005 bombing death of former Lebanese Prime Minister Rafik Hariri. But the government has already rejected that demand.

Bhutto had strong connections to Britain, having spent much of her eight years in self-exile in London before she returned to Pakistan in October to participate in elections.

Rioting that erupted after Bhutto’s death has killed nearly 60 people and caused tens of millions of dollars in damage, particularly in her home province of Sindh. Referring to the violence, Musharraf accused “many miscreants and some political elements” of taking advantage of the tragedy to loot and plunder.

But he had reconciliatory words for Bhutto’s supporters, saying their slain leader had wanted to promote democracy and end terrorism.

Musharraf, who took power in a 1999 coup and recently declared six weeks of emergency rule in an apparent bid to cling to the presidency, said he had wanted elections to go ahead as planned on Jan. 8. But he supported the decision to delay the vote until Feb. 18 because of the rioting.

While Bhutto’s party condemned the delay and said the government did not sincerely want to hold fair elections, Zardari said their party would run anyway – a boost to Musharraf’s hopes to engineer a democratic transition. Zardari backed off from threats to call street protests if the vote was postponed.

“We have decided to take part in the election,” he said. “People should be peaceful and express their anger through their ballots.”

The party of former Prime Minister Nawaz Sharif quickly followed suit.

“We will not leave the field open for the king’s party under any circumstances,” party spokesman Ahsan Iqbal told The Associated Press, referring to the ruling party, which is allied to Musharraf.

The opposition alleged authorities were postponing the vote to help the ruling party, amid expectations that Bhutto’s group could get a sympathy boost at the polls. The ruling party could also suffer a backlash because of Bhutto’s claims it had plotted to kill her, a charge it vehemently denies.

Ruling party spokesman Tariq Azim denied his group would benefit from the delay.

Election Commission head Qazi Mohammed Farooq said the unrest after Bhutto’s dead, which led to the destruction of 10 election offices, made it impossible to hold the election on time.

However, Talat Masood, an independent political analyst, said the delay was “mostly about politics.”

“The (election) problems are only confined to a few districts. Musharraf naturally thinks if a hostile parliament comes in, he has no future.”

Pakistani troops, meanwhile, killed up to 25 suspected militants Tuesday in a remote region close to the Afghan border where al-Qaida and Taliban fighters operate. The fighting followed the abduction of four soldiers, said army spokesman Gen. Waheed Arshad.

The government has blamed South Waziristan-based militant leader Baitullah Mehsud for Bhutto’s murder; he has denied involvement.

In his address, Musharraf did not explicitly blame Mehsud. But he appealed to the media and Pakistanis to “expose” him and another prominent pro-Taliban militant leader based in the Swat Valley, Mullah Fazlullah, whom he also accused of orchestrating suicide attacks.

Associated Press writers Munir Ahmad in Islamabad and Zarar Khan in Naudero contributed to this report.