GAZA (Reuters) -Israeli troops and armor crossed into the central Gaza Strip on Thursday, killing three Hamas Palestinian gunmen in clashes.

An Israeli army spokeswoman said soldiers had carried out a routine operation about a kilometer (half-mile) inside Gaza to locate militants, including those involved in rocket attacks against Israel, and to find smuggling tunnels used by gunmen.

Palestinian ambulance worker Azmi Abu Dalal said Israeli forces seized him and several of his colleagues when they tried to evacuate a wounded Palestinian from a security post Hamas gunmen had been using and which the army took over.

Abu Dalal said soldiers took them to a nearby house and then used them as human shields to exit the area.

“We stayed in their custody for three hours,” the medic said.

The Israeli military spokeswoman said she was checking the report. Israeli law bans the army from using human shields.

The Islamist Hamas movement seized control of Gaza last month after routing the Fatah forces of Western-backed Palestinian President Mahmoud Abbas.

Palestinian medics said two other militants were wounded in the clashes in al-Maghazi refugee camp. The military spokeswoman said troops fired at Palestinian gunmen who had edged towards Israeli forces and had ignored calls to stop and warning shots.

Israeli soldiers were later seen taking over and destroying a security post. It was unclear if it was the same one Abu Dalal described.

Israel withdrew troops and settlers from the Gaza Strip in 2005 after 38 years of occupation, but it has carried out armed incursions and missile strikes in efforts to stop Palestinian militants firing rockets into the Jewish state.

Israeli aircraft also attacked several militants who came close to troops during the raid, the military spokeswoman said.