LONDON (AP)- Police explosives experts were examining suspicious material found in a north London apartment connected to two men suspected of planting failed bombs, both identified as African immigrants who moved to Britain as children.

Yasin Hassan Omar arrived in Britain from Somalia in 1992 at age 11, the Home Office said. The 24-year-old, a Somali citizen with British residency, is suspected of attempting to blow up a subway train near Warren Street station.

Muktar Said Ibrahim, 27, also known as Muktar Mohammed Said, came to Britain in 1990 from Eritrea, his family said. He was granted residency in 1992 and British citizenship in September 2004, the Home Office said.

Both are the children of refugees, the government said.

Somalis have been the largest group of asylum seekers over the last decade, with Eritreans in the middle of the pack, according to the Home Office. Though Black Africans, as they are characterized in the 2001 British census, only represent 0.8 percent of the total British population, the vast majority of 78 percent live in London.

Said attended his local north London high school in the Stanmore neighborhood between 1991 and 1994, when his family said he moved away from home, returning only rarely to visit.

&#34We were shocked when we saw Muktar”s picture in the national news,&#34 the family said in a statement. &#34We immediately attended the police station and made statements to the police. We would suggest that anyone with information contacts the police.&#34

Neighbor Sarah Scott remembered a discussion with Said last November about religion, and his reaction when she told him she was an atheist.

&#34He said I should (believe in God) and that he was going to get me some information,&#34 the 23-year-old said. He returned with a booklet called &#34Understanding Islam,&#34 in which he had highlighted key passages.

&#34Anyone who says ”there is no God except Allah” and dies holding to that will enter paradise,&#34 she recalled one passage as reading.

She said he had never talked about terrorism, but did express his general disgust with society.

&#34He talked about evil spirits, he said there were a lot of evil spirits around because everyone was evil around here,&#34 she said.

Police were trying to determine whether the failed July 21 bombings were connected to the deadly July 7 attacks that killed 52 people and the four suicide bombers.

On Tuesday, police explosives experts were examining what they called suspicious &#34material&#34 found in a search of Omar”s apartment. Said had recently visited the apartment, according to Peter Clarke, head of the Metropolitan Police anti-terrorist squad.

&#34We are taking things away from the apartment but we have not yet done analysis on what it is,&#34 a police spokeswoman said on customary condition of anonymity.

They also impounded a white Volkswagen Golf near the apartment in connection with their investigation of the July 21 bombing attempts, the spokeswoman said.

&#34We checked the car to see if there were any explosives on it and there were not, but we took it away for further forensic examination,&#34 she said.

Police have been searching Omar”s apartment in a concrete high-rise since raiding it late Monday.

A spokeswoman for the London borough, the Enfield Council, told The Associated Press that Omar had been the registered tenant in the apartment since 1999, receiving 75 pounds (US$130) a month in government housing benefits until May.

Police also were questioning five people arrested in connection with the July 21 attacks.

The bombs, which failed to fully detonate, were stored in clear plastic food containers and put into dark-colored bags or backpacks. Clarke said those four bombs were similar to another found abandoned in a park Saturday, raising fears that a fifth bomber is on the loose. He appealed Monday to shopkeepers who may have sold the containers for more information.

A police spokesman, also on customary condition of anonymity, said he could not divulge how the response had been since then.

&#34If we tell the public that, we”re telling the criminals as well,&#34 he said.

In general, he said between the July 21 attacks and July 25, the police force received 1,150 calls to its anti-terrorist hot line. &#34We”re evaluating any and all the information given to us,&#34 he said.

Elsewhere, counterterrorism agents in northern France took two men in for questioning on Tuesday about last year”s deadly Madrid train bombings, French police said.

The suspects, a Moroccan and his son, who has French nationality, were taken into custody at their home in the northern town of Wervicq, near the Belgian border, police and judicial officials said.

They are being held in nearby Lille by agents of the DST counterterrorism service, the officials said. The men”s names emerged in an investigation by Spanish police probing the 2004 train bombings in Madrid, which killed 191 people and injured more than 1,500. French police said their link to the investigation was unclear.