MOSCOW — Russian investigators probing the deadly bombing at Moscow’s largest airport were focusing on up to 10 people from the volatile Caucasus region as possible suspects, a state news agency reported Thursday.

Suspicions initially fell on Chechen rebels for being behind Monday’s blast at Domodedovo Airport that killed 35 people and wounded 180. Chechen rebels have claimed responsibility for a number of deadly attacks over the years, including ones against the Moscow subway and at the same airport.

No one has yet claimed responsibility for the latest attack and Prime Minister Vladimir Putin, perhaps sensitive about his failure to contain Chechnya’s Islamist rebellion, insisted Wednesday there was no initial indication of a Chechen connection. But Chechen rebels have inspired Islamist insurgent activity elsewhere in the Caucasus and the state RIA Novosti agency said up to 10 people from there are being viewed as possible suspects.

Yunus-Bek Yevkurov, the regional president of the province of Ingushetia west of Chechnya, said Thursday that Chechen rebel leader Doku Umarov or some other leaders of the Islamist insurgency likely were behind the airport bombing, the ITAR-Tass news agency reported. Yevkurov himself was badly wounded by a suicide bombing of his convoy in June 2009.

The Kommersant newspaper reported that police attention is focusing on an insurgent group called the Nogai Brigade, which reportedly observes the strict Wahhabi form of Islam.

The group emerged in the early part of the last decade in the Stavropol region and sided with Chechen separatist groups.

Kommersant, citing a source close to the bombing probe, said an ethnic Russian member of the group was of particular interest to investigators

The man is believed to be connected to a woman arrested in January for allegedly planning a suicide bombing in Moscow.