Two more people have been arrested in connection with the London subway bombing last week in Parsons Green, bringing the total number of people arrested to five.

According to local police, two men — aged 30 and 48 — were arrested in Newport, Wales, just after 5 a.m. under the Terrorism Act. Another man, age 25, was arrested in Newport on Tuesday evening.

Two other men, ages 21 and 18, were also arrested on Saturday in connection with the bombing. Police are not yet releasing the identities of these individuals.

The Sept. 15 London Underground attack injured 30 people, as the homemade bucket bomb did not fully explode. Police believe this limited the number of casualties in the attempted rush hour bombing.

"This continues to be a fast-moving investigation," Commander Dean Haydon, head of the Metropolitan Police Counter-Terrorism Command said in a press release. "A significant amount of activity has taken place since the attack on Friday. We now have five men in custody and searches are continuing at four addresses."

London reduced the terror threat from critical to severe over the weekend, but police reminded the public to remain vigilant and report any suspicious activity.