Twitter’s shares jumped 16% in early trading in the US on Thursday after the company reported better than expected revenue and profits, but users declined by 9 million.

The microblogging and messaging service generated income of $789m (£612m) in the third quarter, compared with a $21m loss in the same period last year. Revenues increased by 29% to $758m, far ahead of analysts’ expectations of $700m. The improved figures were welcomed by the market, with Twitter’s shares rising by $4.41, or 16%, in pre-market trading to $31.95.

The number of active users dropped by 9 million to 326 million, however, as Twitter deletes fake and offensive accounts. Its chief executive, Jack Dorsey, said the decline in users would continue because of action taken to “prioritise the long-term health of Twitter while growing the number of people who participate in public conversation”.

“We’re achieving meaningful progress in our efforts to make Twitter a healthier and valuable everyday service,” Dorsey said. “We’re doing a better job detecting and removing spammy and suspicious accounts at sign-up.”

Twitter said the number of its daily active users rose by 9% year-on-year, weaker than an 11% jump in the previous quarter and its slowest growth rate in two years. The company does not disclose the total number of daily users.