Gregory Johnsen: A new and terrifying level of violence

It is difficult to tell, at this early stage, who is responsible for the kidnapping feared to have resulted in the deaths of nine hostages in Yemen. Whoever it was, their killing represents a new and frightening stage of violence, something more suited to the war in Iraq than to Yemen.

Kidnappings have long been a part of the local political landscape. Tribes often hold foreign tourists hostage as a way of forcing the government's hand on any number of local issues. The overwhelming majority of these cases are resolved fairly quickly and peacefully. The one exception was in 1998, when three Britons and an Australian were killed. But they were not executed. Instead these deaths took place during a rescue attempt.

The government initially accused the Huthis, a northern rebel group, of kidnapping the foreigners, which the group has denied on its website. If government accusations are true it would represent a significant departure from the tactics that the Huthis have espoused to date. The fighting, which began in June 2004, is largely a local conflict that grew out of government neglect and opposition to sectarian concerns in Saada throughout the 1990s.

There have been five separate rounds of fighting since 2004, which has given the conflict an evolving logic all its own. The war is no longer the same one as when it began. Different tribes have been brought into the conflict on all sides, as it has been manipulated by various groups and individuals to fit their own short-term interests, while also moving beyond the control of many of these actors.

The murky nature of the war has led some to speculate that a rogue cell within the Huthi movement may have been responsible, and while possible such a scenario is not probable.

The style of the kidnapping and executions suggests al-Qa'ida, which has grown stronger in Yemen over the past year as the government has been distracted by the war against the Huthis. Al-Qa'ida's commander in the region, Nasir al-Wahayshi, recently threatened non-Muslims in Yemen with death if they did not leave the country. Al-Qa'ida has consistently stated that its goal is to "expel the infidels from the Arabian Peninsula".

Yemen arrested a suspected al-Qa'ida financier on Friday, and while the timeline is probably too quick to suggest revenge as a motive for the executions, the significant amounts of cash he was carrying is a worrying indicator for future attacks.

If al-Qa'ida was behind the executions, it will probably post a statement of responsibility to jihadi forums in the coming days. One other possibility suggests that the group may remain silent even if responsible, as a way of casting blame on the Huthis. Al-Qa'ida has learned that the more chaotic Yemen is, the more room it has in which to operate.

Gregory Johnsen is a PhD candidate at Princeton University and a former Fulbright fellow in Yemen