British police arrested two more persons Sunday night, suspected of being connected to the failed car bombings in London and Glasgow at the end of last week.

British police announced Monday that two more persons had been arrested Sunday night in connection to the three attempted attacks last week.

Police said the two men, aged 25 and 28, had been detained in Paisley, a small town near Glasgow, in Scotland. The two are believed not to be of Scottish origin. They were arrested due to “intensive police operations” in Paisley, police in Scotland said.

The two recent arrests raise the number of people detained over the car bombings to seven. “This continues to be a fast-moving investigation,” Assistant Chief Constable John Malcolm of Strathcylde police in Scotland said, as quoted by Reuters. “I would continue to urge people to be vigilant.”

British authorities have not disclosed any of the identities of the seven persons detained. It is suspected that the attacks, twin car bombings in London on Friday and a fuel-laden Jeep driven into Glasgow airport on Saturday were planned out by a group supporting al-Qaeda.

One of the persons detained is a 26-year-old man arrested Saturday evening in Cheshire, northern Britain. He is a neurologist. He was driving with his wife, who has also been arrested, and a child.

One of the men in the Jeep that crashed at Glasgow Airport is reportedly also a doctor. He is being treated for severe burns in the Royal Alexandra hospital in Paisley. The other man in the Jeep has been arrested as well.

Home Secretary Jacqui Smith said Monday that the failing of the attacks was not just “luck”: “I don't think it is luck, I think it is members of the public keeping an eye out, I think it is incredibly brave police officers and explosives officers, I think it is intelligence that is looked at very carefully.”

She will make a statement to parliament Monday afternoon. She has worn British citizens to remain on alert, saying Britain was facing a “serious and sustained threat of terrorism.”