An obscure Palestinian militant group is claiming responsibility for a West Bank attack that killed two Israeli police officers this week. But Israeli and Palestinian security officials are casting doubt on the claim.

Sunday's shooting was the first fatal attack in the West Bank in nearly a year.

The Martyrs of Imad Mughniyeh says it was behind the shooting. The group is named after an assassinated Hezbollah mastermind.

It also has claimed responsibility for previous assaults, including a shooting at a Jewish seminary that killed eight students last year.

However, Israeli and Palestinian security officials said Tuesday there is no such group. They believe rogue militants have used the fake name as cover to evade Israeli reprisals.