Mohammad, who served six years in prison for leading thousands of local men across the border into Afghanistan to fight US-backed foreign forces there, intends to persuade Pakistani Taliban leaders to lay down their arms for the long term.
"I ask you to remain peaceful. We have reached an agreement with the provincial governmetn and Nizam-e-Adl (Islamic system of justice) will soon be enforced here," he told his supporters.
"People will soon start getting justice and there will be a durable peace."
Mohammad Musa Khankhel, a reporter for Geo News television channel and The News daily, was killed at the end of the peace march.
"He was picked up by unidentified people after he covered the peace march," Mohammad Essa Khankhel, Musa's brother told Reuters.
A Taliban spokesman in Swat condemned the killing saying "it is the work of those forces who want to sabotage peace efforts in Swat".
Musa was the fourth journalist killed in Swat in the past one year.
News of Monday's ceasefire agreement between the Pakistani government and pro-Taliban fighters has alarmed Nato, the US and other Western powers.
Imran Khan, reporting for Al Jazeera from Mingora, said Nato has officially expressed "concerns" over the deal and that Washington, while yet to comment publicly, was "reportedly furious".
"Privately they [the US] are very concerned. This peace deal, they say, is appeasing the extremists and would only allow them ... to rearm, regroup, and to be able to carry out future attacks," he said.
Our correspondent said that the move would further worry the Americans, who had just approved sending an additional 17,000 troops to Afghanistan in an attempt to repel fighters sympathetic to the Taliban.
Britain also voiced reservations about the deal, with the UK high commission in Islamabad saying: "We need to be confident that they will end violence, not create space for further violence."
However, Asif Ali Zardari, the Pakistani president, said he would only sign the deal to implement sharia across the Malakand division of NWFP if peace is genuinely restored.
Our correspondent said Pakistani Taliban fighters had a number of key concerns that could hamper any peace deal.
"They are worried that religiously it doesn't really satisfy their needs, they would like a much stricter version of sharia," he said.
"Politically they feel Mohammad will be able to take over Swat ... and, economically, the Pakistan Taliban run a number of businesses in this area and they have an informal system of taxation, some would call it violent extortion, which they fear they are going to lose."