Egyptian President Abdel Fattah al-Sisi said on Monday that revenues from the Suez Canal had "decreased by 40 to 50 percent" so far this year due to attacks on shipping by Yemen's Houthi group. 

The canal is one of Egypt's main sources of foreign currency, with Cairo gripped by a severe financial crisis. The Houthi attacks, which the group says are targeted at vessels with links to Israel in solidarity with the Palestinians in the Gaza Strip, have caused many major shipping firms to suspend passage through the Red Sea, which usually carries around 12 percent of global trade.