A man walks at the yard of al-Kabir Mosque in the first day of the fasting month of Ramadan in Sanaa, Yemen, on May 6, 2019. Ramadan is an Islamic religious observance of the ninth month of the Islamic lunar calendar. It begins with the sight of the new moon and continues for about 30 days. For Muslims, Ramadan is considered the holiest month of the Islamic year. (Photo: Xinhua)

Yemeni men read Quran at al-Kabir Mosque on the first day of the fasting month of Ramadan in Sanaa, Yemen, on May 6, 2019. Ramadan is an Islamic religious observance of the ninth month of the Islamic lunar calendar. It begins with the sight of the new moon and continues for about 30 days. For Muslims, Ramadan is considered the holiest month of the Islamic year. (Photo: Xinhua)

A Yemeni man reads Quran at al-Kabir Mosque on the first day of the fasting month of Ramadan in Sanaa, Yemen, on May 6, 2019. Ramadan is an Islamic religious observance of the ninth month of the Islamic lunar calendar. It begins with the sight of the new moon and continues for about 30 days. For Muslims, Ramadan is considered the holiest month of the Islamic year. (Photo: Xinhua)

Yemeni men read Quran at al-Kabir Mosque on the first day of the fasting month of Ramadan in Sanaa, Yemen, on May 6, 2019. Ramadan is an Islamic religious observance of the ninth month of the Islamic lunar calendar. It begins with the sight of the new moon and continues for about 30 days. For Muslims, Ramadan is considered the holiest month of the Islamic year. (Photo: Xinhua)

Yemeni men read Quran at al-Kabir Mosque on the first day of the fasting month of Ramadan in Sanaa, Yemen, on May 6, 2019. Ramadan is an Islamic religious observance of the ninth month of the Islamic lunar calendar. It begins with the sight of the new moon and continues for about 30 days. For Muslims, Ramadan is considered the holiest month of the Islamic year. (Photo: Xinhua)