Satellite images reveal that 2,275 homes were destroyed during a military raid to hunt down militant Islamists in the northern Nigerian town of Baga last month, a rights group has said.
Human Rights Watch said soldiers "engaged more in destruction than in protection" after Boko Haram fighters attacked a military patrol.
The army has not commented on the latest allegations.
It has said 37 people were killed; others say more than 180 died.
The Islamist Boko Haram group has waged an insurgency to create an Islamic state since 2010.
Correspondents say soldiers have often been accused of using excessive force in its efforts to put down the insurgency.
Nigeria's President Goodluck Jonathan regarded the conflict in Baga as "most regrettable and unfortunate", his office said, in a statement on Tuesday.
"He reaffirmed his full commitment to doing all within the powers of the federal government to speedily end the intolerable threats to national security which have necessitated such confrontations," it said.
'Duty of protection'
Human Rights Watch (HRW) has called on the Nigerian authorities to impartially investigate and prosecute soldiers responsible for recent violence in Baga.
It said satellite images it had analysed undermined the military's assertion that only 30 houses were destroyed during the fighting in Baga, a remote fishing community on the shores of Lake Chad, on 16 and 17 April.
Baga residents told HRW that soldiers ransacked the town after Boko Haram killed a soldier during an attack on a military patrol.
Maina Ma'aji Lawan, a senator for the area, told the BBC Hausa service that more than 4,000 houses had been burnt and more than 200 people had died.
Community leaders told HRW that 2,000 burned homes had been counted and 183 bodies identified after the military raid ended.
Satellite images corroborated this account and had identified 2,275 destroyed buildings with another 125 severely damaged, the US-based rights group said.
Israel says one of its fighter jets has shot down an unmanned aircraft sent from Lebanon into Israeli airspace.
A missile brought down the drone about five miles (8km) west of the northern Israeli port of Haifa around 14:00 (11:00 GMT), officials said.
Reports suggest the drone could have been sent by Lebanese militant group Hezbollah, which fought a month-long war against Israel in 2006.
It is the second time in seven months Israel has downed a drone from Lebanon.
Last October, the Israeli air force shot down an unmanned aircraft over the south of the country.
Israeli Prime Minister Benjamin Netanyahu condemned the incident as an "extremely grave" attempt to breach Israel's borders.
"We will continue to do whatever it takes to protect the security of Israel's citizens," he said.
Mr Netanyahu was on his way to the north of Israel in a helicopter when the incident happened. His aircraft landed briefly until the Lebanese plane was shot down.
He recently warned that Hezbollah might try to take advantage of the instability in neighbouring Syria.
Israel says the latest aircraft was detected and monitored while still over Lebanon, and it was shot down by an air-to-air missile fired from an Israeli fighter jet.
"UAVs [unmanned aerial vehicles] pose a serious threat to the state of Israel's security," said an IDF report on the incident. "The IDF will not tolerate any attempt to violate Israel's sovereignty or harm its security."