RIYADH, Saudi Arabia (AP) -- Five Saudi border guards were killed in clashes along the Yemen border and two Saudi pilots died when their Apache helicopter crashed inside Yemen on Tuesday in one of the deadliest days for the kingdom's troops in months.
Saudi Arabia's Interior Ministry said in a statement the border guards were killed in an eight-hour-long cross-border clash with militants from Yemen. The statement, carried on the official Saudi Press Agency, said that at around 6 a.m. on Monday border guards repelled attempts by armed groups to cross Saudi Arabia's southern border from Yemen.
The Interior Ministry did not identify the attackers, but said the clashes took place in Najran. A day earlier, the kingdom's air defense forces shot down a ballistic missile fired from Yemen toward Najran.
The Saudi-led military coalition has been fighting Yemen's Houthi rebels, who hold territory inside Yemen near the Saudi border.
Also Monday, the Saudi-led force said two Saudi pilots died when their helicopter crashed "due to weather conditions," though it did not specify where in Yemen the crash occurred.
Since March 2015, the mainly Arab coalition has been battling the Iranian-allied Houthis who control territory inside Yemen, including the capital, Sanaa. The coalition is backing Yemen's internationally recognized government, which was forced to flee Sanaa and operate out of the southern port city of Aden.
The conflict has killed some 9,000 people and pushed the Arab world's poorest country to the brink of famine. It also created a vacuum that enabled both Yemen's al-Qaida branch and an upstart Islamic State affiliate to seize territory and carry out large-scale attacks.
A cease-fire declared by the U.N. since April 10 remains shaky, with both sides reporting numerous breaches. The Saudi-backed Yemeni government and the Houthis are currently participating in U.N.-brokered peace talks in Kuwait.