The Pentagon has confirmed that the co-founder of Al-Shabaab Ahmed Godane was killed in a US air strike in Somalia.
Officials called it a "major symbolic and operational loss" for the al Qaeda-affiliated organisation.
"We have confirmed that Ahmed Godane, the co-founder of al-Shabaab, has been killed," Rear Admiral John Kirby, the Pentagon press secretary, said in a statement.
A leader of Somalia's al Qaeda-linked militants Ahmed Abdi Godane was the target of an US air strike in Somalia, an US official said.
It is not clear whether the Al-Shabaab leader was hit in the strike, the official added.
Six militants were killed in the attack on two vehicles that were heading toward the coastal town of Barawe, Al-Shabab's main base.
Since taking charge in 2008, Godane has restyled the group as a global al Qaeda player - a transformation that was highlighted when it killed at least 67 people in an attack on a Kenyan shopping mall last September.
An US airstrike hit an area where leaders of Somalia's al Qaeda-linked militants were meeting, intelligence sources told Reuters.
The strike prompted rumours among Somali government officials that it had targeted al-Shabaab leader Ahmed Abdi Godane and other leaders who were suspected to have been at the location, but there was no confirmation they were hit.
Since taking charge in 2008, Godane has restyled the group as a global al Qaeda player - a transformation that was highlighted when it killed at least 67 people in an attack on a Kenyan shopping mall in September.
The US Department of Defence said that its forces had carried out the operation against al-Shabaab and would provide more information "when appropriate".
Two terrorist attacks on the Kenyan coast was not orchestrated by the al Shabaab terrorist network, according to the country's president Uhuru Kenyatta.
Mr Kenyatta said the 65 people were killed by "local political networks", dismissing claims by Somalia's al Shabaab Islamist group that it was behind the assaults.
Speaking to the nation, he said:
"This was not an al Shabaab terrorist attack. Evidence indicates local political networks were involved in the planning and execution of the heinous crime.
"This also played into the opportunist network of other criminal gangs," he said.
Somali-linked Islamist militants, who claimed responsibility for two nights of attacks on Kenyan coastal towns, have said they will "continue" operations in the country.
"We raided villages around Mpeketoni again last night," Sheikh Abdiasis Abu Musab, the spokesman for al Shabaab's military operations told Reuters.
The group also said it had killed as many as 20 people, mostly police, stating: "Our operations in Kenya will continue."
Mbeketoni eywitnesses say Al-Shabaab gunmen executed men in front of their families and killed others who had gathered to watch World Cup football on television.
"The attackers were so many and were all armed with guns. They entered the video hall where we were watching a World Cup match and shot indiscriminately at us," Meshack Kimani said, adding about 10 people were killed there.
"They targeted only men but I was lucky. I escaped by hiding behind the door," he said.
Al-Shabaab, the Islamist terror group claiming responsibility for yesterday's killings, has issued a warning to tourists.
In a statement, the group said, "Kenya is now officially a war zone and as such any tourists visiting the country do so at their own peril."
Al-Shabaab has claimed responsibility for the deadly attacks in Kenya yesterday.
In a statement, the Somali Islamist group said, "Commandos last night carried out a successful raid on the town of Mpeketoni."
As reasons, it cited the deployment of Kenyan troops to Somalia, and what it called Kenya's extra-judicial killings of Muslim scholars - a charge Nairobi has denied.
The UK Government says travelers should not go within 60km of the Kenyan border with Somalia unless absolutely necessary, because of the threat from terrorist group Al-Shabaab.
Yesterday's attack happened in Mpeketoni, just south of the popular resort of Lamu. This is not within the orange danger zone, though the Foreign Office has today updated its website to make travelers aware of the killings.
A spokeswoman at the Foreign & Commonwealth Office said the travel advice is kept under constant review.
Al-Shabaab, the Somali Islamist group with links to Al-Qaeda, has claimed responsibility for yesterday's attacks, according to the pro-Shabaab website Somalimemo.
It goes on to claim that the attacks were revenge for the killing of Muslim clerics.
Kenya sent troops to Somalia in 2011 to help the UN-backed government defeat Al-Shabaab.