BEIRUT (AP) — Israel struck southern Beirut suburbs on Sunday just days after a fragile ceasefire agreement in Washington went into effect.

Israeli Prime Minister Benjamin Netanyahu said the strikes were in retaliation for the Hezbollah militant group firing towards northern Israel earlier. Hezbollah did not immediately claim responsibility for those strikes.

Israel has struck the sprawling urban neighborhoods twice since the first agreement between Lebanon and Israel went into effect on April 17. Strikes over southern Lebanon continue daily, where Hezbollah fighters and Israeli troops have also clashed.

Residents heard three explosions in the area. It was not immediately clear what was targeted in the strikes.

There was no immediate word of casualties.