Israel carried out it first strikes against Houthi targets in Yemen since the Israel-Iran ceasefire, attacking ports and a power plant around midnight local time Sunday night into Monday morning.

The Houthis then responded with an apparent missile attack on Israel. The Israeli military said that it attempted to intercept the two missiles launched by the Houthis, but they appeared to make impact, though no injuries have been reported. Sirens sounded in the West Bank and along the Dead Sea.

Iran’s military denied firing on Israel, state media reported — but explosions boomed and sirens sounded across northern Israel midmorning. Earlier, both Israel and Iran had accepted the ceasefire plan to end their 12-day war.