The India Meteorological Department on Wednesday issued a red alert warning for Mumbai, Pune and five others districts of Maharashtra as heavy rain continued in the state.

A red alert signals extremely heavy rainfall, while an orange alert is for heavy to very heavy rain. For Mumbai, the weather department has issued an orange alert on Thursday, but for Pune, it sounded a red alert for both the days.

Palghar and Thane are likely to receive “extremely heavy rainfall at isolated places” on Wednesday and “heavy to very heavy rainfall at a few places” on Thursday, the Regional Meteorological Centre in Mumbai said in a bulletin.

Raigad, Ratnagari and Satara are likely to receive extremely heavy rainfall on both Wednesday and Thursday, according to the weather department.

Mumbai was hit by heavy rain for the fourth straight day on Wednesday, leading to flooding in several areas.

The city recorded more than 23 millimetres of rain within the 24-hour period ending 8.30 am on Wednesday, the Hindustan Times reported. So far, Mumbai has recorded nearly 990 millimetres of rainfall in the month of July, much higher than the weather department’s normal level of 827 millimetres.

“These rains are not thunderstorm rains like we saw on early Sunday,” an official from the Regional Meteorological Centre in Mumbai told the Hindustan Times. “It is the result of very strong westerly winds bringing in moisture from an active monsoon trough that runs along coastal Maharashtra. Mumbai could easily see another 50 to 60 mm of rain by this [Wednesday] evening.”

Heavy rainfall in the city has led to several deaths. On Sunday, 19 people died after a wall collapsed in Chembur. Ten others were killed after their huts collapsed in Vikhroli. One person died in a wall collapse in Bhandup, while another was electrocuted in Andheri West.

The National Disaster Response Force teams joined the police and the fire brigade to carry out rescue operations.