The Gujarat earthquake had its epicentre at Vamka taluka in Kutch, which is an active fault line, scientists at Institute of Seismological Research said.
Besides Kutch district, tremors were experienced in parts of Saurashtra region. An aftershock measuring 2.9 was also recorded.
Maharashtra earthquake's epicentre was located in Goshatwadi village, about 10km from Koyana dam in Satara, the Meteorological department office said.
The shocks were also felt in Sangli, Kolhapur and Ratnagiri districts of Maharashtra, sources in the Met department said. The Koyna dam, situated in a quake-prone region, is safe, officials said.
An aftershock of 4.4 magnitude was registered an hour later, Met added.
Tremors were also felt in parts of Karnataka bordering Maharashtra, including Belgaum and Gulbarga.
"These are too minor earthquakes. Small earthquakes occur in Indian subcontinents. There are various sources and mechanism of earthquakes. Scientific investigations needs to be still investigated," said RS Dattatreya, Director, Seismology Division, Meteorological Department.
No damage to life and property has been reported so far.
Among those who felt the tremors in Mumbai were megastar Amitabh Bachchan, who resides in suburban Juhu. "Earthquake in Mumbai ! Did you feel it.. I did..Shutters and building shook twice for few seconds," Mr Bachchan tweeted.