Al Jazeera on Monday said that 1,000 Qatari soldiers had crossed the al-Wadia border crossing from Saudi Arabia.
"A second contingent of Qatari soldiers has entered the al-Wadia border crossing," an Al Jazeera correspondent in southern Saudi Arabia was quoted as saying.
BOMBING, AIR POWER
A source close to the Qatari military confirmed the report.
"The operation in Sanaa will use extensive bombing, air power, to support the ground offensive," the source said.
Qatari and coalition officials did not immediately respond to requests for comment.
Egyptian officials told Reuters that an unspecified number of Egyptian troops would arrive in Yemen on Tuesday and Saudi-owned Arabiya newspaper quoted sources as saying that 6,000 Sudanese troops would soon join the fight inside Yemen.
The Sudanese government did not comment on the report but it was corroborated by the source close to the Qatari military.