GAZA CITY, Gaza Strip - The Hamas-led Palestinian government said Wednesday it is activating a new security unit made up of militants, despite a veto by moderate Palestinian President Mahmoud Abbas.

The announcement further heightened tensions between Hamas and Abbas' Fatah Party. It came just hours after two Hamas militants were killed in mysterious drive-by shootings in Gaza.

The Hamas-led government and Abbas have been wrangling over power since the Islamic militant group took power in late March.

A key area of dispute is control over the security forces.

As president, Abbas wields considerable power and carries the title of commander of the security forces.

Three of the six security branches report to the Hamas-controlled Interior Ministry, but Abbas has placed a loyalist in a commanding position of the most important one.

In response, Hamas last month announced the creation of a special unit to be made up of former militants. Abbas vetoed the formation of the unit, seen largely as Hamas' private army.

In direct defiance of Abbas' veto, Interior Minister Said Siyam of Hamas said Wednesday that the unit would begin operations. The unit is to be headed by Jamal Abu Samhadaneh, a militant high on Israel's wanted list.