Ministers in Belgium have offered to resign after failing to keep tabs on Islamic State (Isis) militant Brahim El Bakraoui, who was released by Turkey then blew himself up at Brussels airport. The news comes as it has emerged that three of the suspected bombers were on US counter-terror watch lists.

El Bakraoui was said to have blown himself up at Brussels' Zaventem Airport, killing at least 11 people, after Turkish officials warned Belgium that he was a "foreign fighter" but their warnings were "ignored". He had already been deported to the Netherlands at his own request, but Dutch authorities said he was not on any wanted lists so they had no reason to detain him.

His brother, Khalid, is believed to have blown himself up at Maelbeek metro station, where an additional 20 people are thought to have died, making the attack the deadliest in Belgian history. One other suspect who was seen with them on security cameras, is now on the run, with a fifth suspected bomber filmed in the metro attack who may be dead or alive.

On Thursday 24 March Interior Minister Jan Jambon and Justice Minister Koen Geens tendered their resignations to Prime Minister Charles Michel. The Belgian PM rejected their offers and Jambon said afterwards according to Reuters: "In time of war, you cannot leave the field," Jambon, a right-wing Flemish nationalist, declared.

Today it emerged that both Bakraouis were both on US government counter-terrorism watch lists even before the arrest of Salah Abdeslam on Friday 18 March. Another suspected bomber, who was wearing a white jacket and a black hat, was also said to have been on the US terror watch list – and is thought to be still on the run.

The suicide attacks claimed by Daesh (Isis) wounded at least 300. The Belgian health ministry said 121 of the injured were still in hospital, 63 of them in a serious condition.

Now, three days after the attacks, Belgium has lowered its alert to the second-highest level with Metro stations reopening, but with heavy security still present. Jambon added that he had "missed the chance to seize him (Bakraoui) when he was in Turkey".

He said: "In the circumstances it was right to take political responsibility and I offered my resignation to the prime minister. The prime minister and the inner cabinet requested clearly this morning that I stay on, given the current situation, that in a war situation you cannot leave the field."

More about the Brussels attacks