NAIROBI - It is afternoon in Eastleigh, a vibrant commercial and residential area in Nairobi, Kenya.

Jibril Kassim and his four friends sit near a building adjacent to Moi Air Base, a military establishment, whiling their time away.

Ordinary, the teenagers would be playing football at a field near the military airport, but it is now a month-and-a-half since they played soccer there.

"The field was fenced off to prevent the public from moving near the airport soon after Kenya forces moved to Somalia to fight Al Shabaab militants," Kassim told Xinhua in an interview.

"We can longer play soccer, which is our favourite game, and we hoped to make careers out of it," From a distance, one can see military men in their jungle green outfits patrolling the area near airport.

"You cannot move near that field because the military would not allow you. They may even suspect you for being an Al Shabaab member," Kassim said.

The teenager and his friends are among hundreds of Kenyans feeling the pinch of war on terror as the country intensifies fight against Al-Shabaab insurgents in Somalia.

Since Kenya Defence Forces (KDF) moved into Somalia in October last year, security in the country has been tightened, affecting the lives of many people.

The Al Qaeda-linked militants, Al-Shabaab, on the other hand, have continued to issue terror attack threats, the latest having been made on January 5.

The threats are hovering over Kenya, with many countries warning their citizens to be cautious as they go about their businesses in Nairobi.

"We believe terrorists may be in final stages of planning terror attacks. Attacks could be indiscriminate and target places where expatriates and foreigners gather such as hotels, shopping centres and beaches," British Foreign Office warned its citizens on January 7.

The Foreign Office noted that the main source of terrorist threat in Kenya comes from the Somali militant outfit, Al-Shabaab.

"We feel our dreams to become football stars have been shattered because of the ongoing war on Al Shabaab. We may never play on that field again as long as Kenya forces are still in Somalia," said Kassim, who was hoping to join one of Kenya's Premier League teams.

Kassim said they have tried to seek an alternative playing ground in vain.

"There are no more playing grounds around. Most of them have been taken away by developers, who are putting up houses. We have to travel to Huruma, which is about ten kilometres away to find a playing ground. This journey costs 0.5 U.S. dollars, we cannot afford that," he said.

Like the teenagers, other residents of the area have been equally affected by heightened security.

"The soldiers are patrolling all over the area. You cannot walk near the barracks while carrying a bag without army officers stopping you. They will demand to know what you are ferrying. It might be a bomb," said George Karanja, a resident.

Karanja observed many residents in the fastest growing commercial and residential area in Nairobi were not used to such security checks.

"In fact, we were not used to seeing soldiers patrolling Eastleigh, but it has become common. The war on Al Shabaab has changed the way things are done," he said.

Karanja noted that the huge population of Somali nationals in the area has made police heighten patrols and search for Al Shabaab sympathisers.

But it is slum residents who have bore the brunt of Kenya's fight against Al-Shabaab.

Most slums in Nairobi, which were bordering major installations like airports, have been demolished in the past months rendering residents homeless.

Among informal settlements that have fallen because of Al Shabaab include Mitumba, Kyang'ombe and a formal residential area, Syokimau, which were bordering Wilson and Jomo Kenyatta International Airport respectively.

Kenyan authorities have planned demolition of other slums, which pose security threats to state installation. At Kiambiu slum, which borders Moi Air Base in Eastleigh, residents are living in fear of being evicted.

"We do not know where we will move to because we do not have alternative places to live," said Frida Auma, a resident. "We were told last year that the slum is a security risk to the airport, therefore we must move."

Auma is certain that were it not for the war on Al-Shabaab, they would still be living comfortably in the area.

"Al Shabaab has completely disrupted lives of many people. The war is being fought thousands of miles away but we are suffering its consequences here. We do not know for long this will go on, but we hope it ends soon," said Auma.

As the war on Al-Shabaab heightens, Kenyans have been asked to cooperate with police to defeat threats of terror attack, which hangover the East African nation.

In the Central Business District, it is now the norm for people to be frisked and undergo various checks as they enter business premises.

"I appeal to everybody in Nairobi to be extra alert and to take the security measures being undertaken positively," city police boss Anthony Kibuchi told residents.