Kenyan fighter jets have bombed positions of militant Islamist group al-Shabab in neighbouring Somalia, a military spokesman has told the BBC.
The warplanes had targeted two camps in the Gedo region, used by al-Shabab to cross into Kenya, the spokesman added.
This is Kenya's first response to an al-Shabab assault which left 148 people dead at Garissa University last week.
President Uhuru Kenyatta had vowed to respond to the attack "in the severest way possible".
Kenyan army spokesman David Obonyo told the BBC that the military had responded to "threats" by launching the air strike on Sunday night in the remote region.
No further details of the operation were available at this stage, he said.
Two camps had been destroyed, he said, adding: "The bombings are part of the continued process and engagement against al-Shabab, which will go on."
The attack on Garissa University, about 150km (90 miles) from the Somali border, was the deadliest by al-Shabab in Kenya.
The al-Qaeda affiliate says it is at war with Kenya, and wants it to withdraw troops sent to Somalia in 2011 to help the weak government in Mogadishu fight the militants.
Governors and MPs from north-eastern Kenya have called for the closure of the Dadaab refugee camp, where about 500,000 people who fled conflict in Somalia are taking shelter.
They told a news conference in the capital, Nairobi, that the camp was used by al-Shabab as a training and coordination centre.
Aid agencies have rejected previous calls for the closure of Dadaab, the largest refugee camp in Africa.
An MP in Garissa, Aden Duale, said Kenya should "engage" with the international community to step up patrols along its long and porous border with Somalia.
Meanwhile, Kenya's government has denied accusations that its security forces were slow to respond to Thursday's assault on the university.
Mr Kenyatta's spokesman Manoah Espisu told the BBC that the military was at the scene within minutes of the attack, and had helped save the lives of many students on campus.
Local media reported that it took special forces several hours to arrive at the university because of delays in their flight from Nairobi.
The attack ended when the four militants were killed by police more than 15 hours after they stormed the university.
One of the gunmen has been named as Abdirahim Abdullahi, a law student who graduated from Nairobi University in 2013.
His father is a local chief, and had reported his son missing, according to local media.
A former fellow student of Abdullahi told BBC Newsday that he had been a "charming fellow" who did not show any sign of holding militant views at university.
"He was very intelligent… I was very shocked that a person I sat with in class – what would drive someone to change so much?" said the former student, who asked not to be identified for fear of reprisals.
- The last time a national budget was rejected in Ghana
- Speaker’s ruling on 2022 budget has no binding effect on Parliament – Majority Leader
- We’ll not tolerate any disrespect from Speaker – Majority Leader after walkout
- 2022 Budget rejection: We did not take uncompromising positions – Ato Forson
- Join NDC’s presidential race if you are interested in being number 1 – John Boadu to Alban Bagbin
- ‘I did nothing wrong’ – Asiedu Nketia justifies his presence in Parliament
- ‘Killer budget isn’t coming back; we’re burying it for good’ – Ablakwa
- Playback: Newsfile discusses 2022 budget and energy sector debt
- Dela Sedode: Christ Me! Bagbin
- 2022 Budget: What was wrong with Finance Minister requesting for further engagement? – Majority Leader quizzes
SOS-GrEEn sensitizes residents of New Edubiase on violence against women
Ghana Beach Soccer has potential to be a huge success in future – FIFA Instructor Angelo Schirinzi
Kinaata hopes successes of Hasaacas Ladies will inspire Sekondi Hasaacas
Okyeame Kwame and Adansi Travels launch family fun tour on GTA’s Accra City Tour bus to promote Ghana
Ghana’s energy sector debt likely to hit ₵7 billion by close of 2021 – Energy expert
Three percent withholding tax on unprocessed gold slashed to 1.5 percent-Abu Jinapor
Government must be lauded for exemplary leadership – Atta-Akyea
Haul John Boadu before Parliament if you find his comments contemptuous – Nyarko Osei tells Kwame Agbodza
Government approves ¢43m to Ghana Veterinary Medical Association
Agri-impact wins big at the at the Ghana Agribusiness Excellence & Leadership Awards
RUGBY 7S WORLD CUP QUALIFIERS: GHANA BOOKS SEMI FINAL PLACE
Allow cool heads to prevail – Ato Forson cautions Majority Caucus against plans to challenge Speakers ruling on the budget
Upper East Region records 65 defilement cases in 2020
Over 300 suspected criminals arrested in military operation in northern Ghana
Depreciation of cedi part of reasons for energy sector debt – Energy Analyst