BAGHDAD, (AP) – Iraq’s government says it will investigate a shootout earlier this week between Iraqi fishermen and Kuwaiti coast guards that left one dead.

Iraqi government spokesman Ali al-Dabbagh said Tuesday that the skirmish killed a Kuwaiti officer, whose men retaliated by sinking the Iraqi boat in the Persian Gulf.

Al-Dabbagh said four Iraqi fishermen were detained by Kuwaiti forces after the Monday incident.

Kuwait’s government said the fishing vessel had strayed into their waters and the Iraqi fisherman opened fire on the coast guard.

Ties between Kuwait and Iraq have been strained for years, going back to when former Iraqi president Saddam Hussein invaded the small nation in 1990.