Al-Shabab fighters have killed at least 15 people in a second night of attacks on Kenya's coast, barely 24 hours after an attack near the coastal town Mpeketoni left at least 48 people dead, according to Kenya's interior minister.
However, a spokesman of the Somalia-based armed group claimed on Monday to have killed 20 people, mostly security officers, in the overnight attack on Poromoko, a village located between the city of Mombasa and the Kenyan border.
Al-Shabaab also said it would continue its campaign in East Africa's largest economy, saying they want to punish the government for sending troops to Somalia to confront their fighters.
Sunday's assault - the first of the two attacks - in Kenya's tourist hub in Lamu county was the biggest since the deadly Westgate Mall raid last September in the capital Nairobi.
"The Mpeketoni raid was carried out in response to Kenyan military's continued invasion and occupation of our Muslim lands and the massacre of innocent Muslims in Somalia," al-Shabab said.
Joseph Ole Lenku, the interior minister, promised on Monday to pursue the attackers.
"These attacks are unfortunate and the perpetrators must be held accountable," he said in Mpeketoni where he was jeered by locals.
"We condemn yesterday's killings and the latest attack today where about 15 other people were killed and houses burnt."
In a statement sent to Al Jazeera on Monday, al-Shabab said the Kenyan government was "fighting a losing war" and telling tourists to stay away.
Al-Shabab said it targeted Mpeketoni on Sunday because it was originally a Muslim area that was "invaded and occupied by Christian settlers".
"The prospect of peace and stability in Kenya will be but a distant mirage," the al-Shabab statement said.
"Brace yourself for the depredations of war and that which you have with your hands sown."
Al Jazeera's Rawyah Rageh, reporting from Mpeketoni on Monday, said that residents were "shocked" about how the assault lasted for hours, with the attackers fleeing with minimal resistance.
She said the attack did not target foreigners in Kenya. "Attacks frequently carried out by al-Shabab target foreigners, but the latest one targeted locals in a small town," she said.
Kenya sent troops into Somalia in late 2011, after al-Shabab fighters carried out a series of raids on Kenyan soil.
It has fought a seven-year campaign to impose its interpretation of Islamic law inside Somalia.
Kenya has experienced a drop in tourist arrivals in recent months following gun and grenade attacks blamed on al-Shabab or its sympathisers.
In May, explosions in Nairobi and the coastal city of Mombasa led the UK, US, France and Australia to issue warnings about travel to Kenya, and at least 400 tourists cut short their holidays and left hotels along the Indian Ocean coast.
Kenya called the alerts "unfriendly", saying they would increase panic and play into the hands of those behind the assaults.