Al-Shabab fighters claim they killed at least 15 people in a second night of attacks on Kenya's coast, but the country's president says the attacks were the work of "local political networks" and gangs.

The latest attack happened overnight on Tuesday in Pomoroko, a village located between the city of Mombasa and the Kenyan border with Somalia, where the armed group is based.

The attack come after 48 people were killed in Mpeketoni in the early hours of Sunday. Al-Shabab claimed they carried out the attack to punish the Kenyan government for sending troops to Somalia.

However, President Uhuru Kenyatta denied al-Shabab's role in the attacks, instead blaming what he called "local political networks" and criminal gangs.

Analysis: Al-Shabab's attacks in Kenya

"The attack in Lamu was well planned, orchestrated and politically motivated ethnic violence against the Kenyan community, with the intention of profiling and evicting them for political reasons," Kenyatta said on Tuesday.

"This therefore was not an al-Shabab terrorist attack, evidence indicates that local political networks were involved in the planning and execution of the heinous crime."

In an interview with Al Jazeera, opposition member and senator Anyang Nyong'o said that the security situation in Kenya was getting "very serious" and blamed Kenyatta's government for carrying out "reactive action" instead of "preventive" measures to stop the attacks.

He also dismissed an earlier statement linking the opposition to the attacks, saying the allegations were "extremely irresponsible."

'Fighting a losing war' 

Sunday's assault in Mpeketoni, in Kenya's tourist hub, was the biggest since the deadly Westgate Mall raid last September in the capital Nairobi.

In a statement sent to Al Jazeera on Monday, al-Shabab said it would continue its campaign in East Africa's largest economy.

"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," it said.

The group said the Kenyan government was "fighting a losing war" and telling tourists to stay away.

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.

Al Jazeera's Rawyah Rageh, reporting from Mpeketoni, said residents were in fear that al-Shabab will carry out more attacks.

Kenya has experienced a drop in tourist arrivals in recent months following gun and grenade attacks blamed on al-Shabab or its sympathisers.

Source: Agencies