Tropical Storm Ingrid and the remnants of Tropical Storm Manuel have drenched Mexico's Pacific and Gulf coasts with torrential rains, flooding towns and cities and sparking a national emergency that authorities said had caused at least 33 deaths.
The governor of the Gulf Coast state of Veracruz said 12 people were killed when a landslide hit a bus travelling through the town of Altotonga, about 40 miles north-west of the state capital.
Governor Javier Duarte said the death toll could grow as bodies are recovered.
More than 23,000 people have fled their homes in the state due to heavy rains and 9,000 are in emergency shelters.
The heaviest blow fell on the southern coastal state of Guerrero, where Mexico's government reported 14 confirmed deaths. State officials said people had been killed in landslides, drownings in a swollen river and a truck crash on a mountain highway.
Civil Protection co-ordinator Luis Felipe Puente said stormy weather from one or both of the two systems also caused three deaths in Hidalgo, three in Puebla and one in Oaxaca.
Authorities in the Gulf states of Tamaulipas and Veracruz evacuated more than 7,000 people from low-lying areas as the storms closed in, and the prospect of severe weather prompted some communities to cancel Independence Day celebrations planned for Sunday and Monday.
Manuel came ashore as a tropical storm on Sunday afternoon near the Pacific port of Manzanillo, but quickly began losing strength and was downgraded to a tropical depression, although officials warned its rains could still cause flash floods and mudslides. The rains caused some rivers to overflow in Guerrero, damaging hundreds of homes and disrupting communications for several hours.
Manuel was expected to dump up to 15in of rain over parts of Guerrero and Michoacan states, with maximums of 25in possible in some isolated areas. Rains of 5in to 10in were possible in the states of Colima, Jalisco and Nayarit, with possible maximums of 20in in some places. Authorities said the rains presented a dangerous threat in mountains, where flash floods and mudslides were possible.
Ingrid was expected to bring very heavy rains, and a tropical storm warning was in effect from La Cruz to Rio San Fernando. More than 1,000 homes in Veracruz state had been affected by the storm to varying degrees, and 20 highways and 12 bridges were damaged, the state's civil protection authority said. A bridge collapsed near the northern Veracruz city of Misantla on Friday, cutting off the area from the state capital, Xalapa. Thirteen people died in the state earlier this month when a landslide buried their homes in heavy rains spawned by Tropical Depression Fernand.