MEXICO CITY (Reuters) - Mexico’s foreign ministry on Wednesday raised the number of its citizens who died or were hospitalized after enduring sweltering conditions in the back of a truck in San Antonio, Texas, saying seven Mexicans died and 27 remain in hospital.

At least 10 people were found dead over the weekend in the back of a tractor-trailer in the south-central Texas city, with dozens escaping by foot.

At least 100 illegal immigrants, mainly from Mexico and Guatemala, were crammed into the back of the truck. The driver accused of smuggling the illegal immigrants has said he was unaware of the human cargo he was hauling until he took a rest stop.

In a statement on Monday, Mexico’s foreign ministry said four of the 10 dead were Mexicans, as were 21 of the 29 people hospitalized.

However, on Wednesday the ministry said seven Mexicans were now confirmed dead and 27 were still hospitalized. It added that it would provide legal help to survivors of the incident.

The Guatemalan government has confirmed that one of its citizens was among the dead and two others had been found alive.

The nationality of the other two casualties remains unclear.