Palestinian smugglers in the Gaza Strip are facing a deadly crackdown from Egypt.
The Islamic militant group Hamas says Egyptian forces pumped gas into a Gaza smuggling tunnel, killing four Palestinians. Hamas, which rules the Gaza Strip, accused Egypt of committing a "terrible crime" and of killing the Palestinian workers "in cold blood."
Speaking at a Gaza news conference, Hamas spokesman Sami Abu Zuhri called for an investigation and demanded that those responsible to be brought to justice.
There are hundreds of tunnels under the Gaza border with Egypt aimed at bypassing a crippling Israeli blockade. The tunnels bring in food, gasoline and other goods, but are also used by Hamas to smuggle guns, ammunition and rockets.
Under pressure from Israel and the United States, Egypt has been cracking down on smuggling. An underground wall is under construction, but this is the first alleged use of lethal gas. An Egyptian intelligence official denies that gas was used and says the Palestinians apparently suffocated after the tunnel was blown up.
The incident puts further strain on ties between the Islamist regime in Gaza and its Egyptian neighbors.
Hamas accuses Egypt of collaborating with the Israeli blockade. But Egypt has security interests of its own. It fears that the smuggling of weapons and militants on the Gaza border could threaten the lucrative tourism industry in the Egyptian Sinai Peninsula and destabilize the pro-western government in Cairo.